
Class 
Book 



diSI 






COPYRIGHT DEPOSHV 




> 



a 

S3 

. o 

B » 

|§, tp 
2 *-• iS • 

CO sui 03 

— ec S S 

o 

Q. 

c 

8 






a 

z 



1-H c^ 



2 

I 



.2 .S ^ fe 



Tiij 



/ 6- SJ 3- c 



1915 EDITION 

THE 

MECHANICS' 
COMPLETE LIBRARY 

OF 

MODERN RULES, FACTS 
PROCESSES, ETC. 



j^'acts About Electricity — How to Make and Run Dynamos 
— All About Batteries, Telephones, Electric Railways and 
Lighting — Engineering Explained — Rules for the In- 
struction of Engineers, Firemen, Machinists, Mechan- 
ics, Artisans and all Craftsmen — Tables of Alloy 
— Useful Recipes — Information Concerning 
Glass, Metal, Wood Working, Leather, Arti- 
ficial Ice-making, Chemical Experiments — 
Glossary of Technical Terms — Electric, 
Oxy-acetylene and Russian Welding. 



FIVE BOOKS IN ONE 



COMPILED BY 

Thomas F. Edison, A. IVK^, and Charles J. Westinghouse 



II 



Copyright, 1915, by Laird & Lee, Inc. 

Copyright, 1900, by Wm. H. Lee. 
Copyright, 1890, 1895, by Laird & Lee. 



CHICAGO 

Laird & Lee, Inc., Publishers 



riechanical Works 



, \ THAT ARE 

\; RECOGNIZED AS AUTHORITIES 



k 



tevens' Mechanical Catechism. 

An entirely new and original work for stationary and marine engi- 
neers, machinists, firemen, and mechanics generally. 250 illustra- 
tions. Fully describes machinery and tools, construction an# 
operation of machines, etc.. etc. Substantially bound, Cloth, $1.00% 
Morocco, marbled edges, $1.50. 

Kilbarn'g Standard Handbook for Kailroad Men. 

Illustrated. Questions and Answers on all points referring to R. R 
Engines, Automatic Air Brakes, Link Motion, Injector Practice 
Br«akdowns, Signals, etc. Keratol binding, with pocket, $1.00. 

The Motorman's Guide. 

By J. W. Gayetty. Illustrated. Everything a motorman should know 
about the care and running of his car. Flexible cloth, red edges, 50c. 

E^ng^ineers' Practical Test and Reference Book. 

For Engineers, Mechanics, Machinists, Firemen, etc. Boilers and 
Engines and how to make them; Engineer's License, Examination 
Questions and Answers. Stiff silk cloth, red edges, $1.00. 

The Mechanical Arts Simplified. 497 pages. Arranged and 
edited by D. B. Dixon. New improved edition. Illustrated. A thor- 
ough and original book of reference for Architects, Iron Workers, 
Boiler Makers, Contractors, Civil and Mechanical Engineers, Fire- 
men, etc. Silk cloth, $1.50. Flexible leather, $^.50. 

IThe Machinists' and Engineers' Pocket Manual. 

An exhaustive treatise on Gear, Valve and Indicator Practice. Vocabu- 
lary of 2,000 mechanical and electrical words. How to connect 
Dynamos and Motors; Shafting Drills, Wire Weights and Resistances, 
Screw Gutting, Properties of Saturated Steam, Fractions, etc., etc. 
Illustrated with mechanical sketches and diagrams. Leather, stained 
edges, gold stamped title, pocket, flap ana button clasp, $1.00* 

The Mechanics* Complete Liibrary. 

676 pages. Illustrated. Five books in one. Mechanics in a nutsheNs. 
Statistics of all kinds. Rules, Processes, Tables, Curious Facts. 
Greatest buildings described. Glossary of technical terms. How to 
make Batteries, etc., etc. Stiff silk cloth, red edges, $1.00; 
Morocco, marbled edges, $1.50. 

Zivicker's Revised Instructor. 

For Artisans, Fire, Marine and Locomotive Engineers. The work of a 
practical mashiniet in the form of questions and answers. Stiff 
cloth, 75c. 

Practical Application of Dynamo Electric Machinery. 

By McFaddkn & jIay. Every Motorman, Lineman, Dynamo Tender 
and Engineer should have a copy. By far the best and cheapest book 
of iO? kind. Flexible cloth, red edges, $1.00. 

For sale by all booksellers and newsdealers, 
or sent postpaid on receipt of price by 

LAIRD % LEE, Publishers. CHICAGO, U. S. A. 

For lul) de£ 'riotions write for our illustrated catalogue. 

©CI,A39iB99 FEB 12 1915 



CONTENTS 



Accidents by Shafting, to prevent 130 

Prom Running Machinery, prevention of 127-130 

to boilers, how to prevent • . 147 

Air Brake. Westinghouse Automatic. j9-74 

Alloy, a new 284 

Alloys and Solders 186 

Altitude above the sea level of various places in the 

United States 424 

Aluminum, how to solder 368 

Ampere the (electrical measure) 538 

Ampere's Rule 487 

Analysis of Boiler Incrustations 155 

Apprentices, points for 301 

Architects, laws affecting 442 

Etc., pointers for 420, 421 

Armature, the largest 165 

Artesian Wells, valuable 344 

Ash Sifter, how made 382 

Atmosphere; effect on bricks 437 

Estimated mean pressure of the 55 

Automatic Sprinklers, care of 185 

Avoirdupois Weight 356 

Babbitt Metal, composition of , 369 

Ball, cast iron, weight of 282 

How to turn a 209 

Bank of England Doors, the 228 

Barrels, how made 234 

Basswood Moldings 445 

Batteries, closed circuit (electrical); electric; galvanic; 
open circuit (electrical); primary (electrical); 

voltaic 536 

Belt, the largest 216 

Belting, camel's hair 289 

How to calculate speed of 332 

Notes on 80 

Rules for Calculating Power Transmitted by 82 

Benzine and its Weight 416 

Bessemer Process, real inventor of 220 

Blowing Off Under Pressure 152 

Boiler Circumferences, points on 88 

Boilers, Steam 45 

Boiler Tubes, cleaning 155 

Boiling 145 

Bolts, weight per 100 207 

Brass Castings, hard and ductile 186 

Cleaning 155 

Its treatment 323-325 

How to lacquer , 219 

Weight of sheet 196, 197 

Breaking Strains of Metals ( 282 



Breathing Apparatus, a new 215 

Bricks, made from refuse of slate quarries 337 

Number of, to construct building 439 

Bronze, bow to make maL.eable 288 

Building Blocks Made of Corn Cobs 445 

Builders, points for 411-413 

Cables, submarine, breaks in 278-282 

Calcimine, how to prepare 445 

Calking 314 

•^ans, fiat top, size and weight 415 

Cast Iron Columns 367 

Cast Iron Columns, safe load for 349, 350 

Cast Iron Columns, safety load 362-364 

Cast Iron Columns, weight of 353, 354 

Cast Iron Piles, action of sea water 210 

Cast Iron Pipes, weight of 410 

Cast Iron, weight per lineal foot 205 

Cathedrals^ dimensions of 441 

Celluloid Sheathing 135 

Cement, a new 284 

A reliable 446 

As used in Paris 344 

for Granite Monuments 394 

Useful 134 

Centigrade and Metric Equivalents 283 

Chemical Substances, common names of 238 

Chimneys, how to cure smoky 459-461 

One that will draw 363 

Sweating of ^ 458 

Table of sizes of 90 

Chinese Cash 414 

China, cost of living in 367 

Chisels, cold 75- 77 

Circles, area of 351 

Circumferences of 352 

';:)isterns, cylindrical, capacity of 292 

Cylindrical, capacity per foot 365 

Clock Movement, self-winding 307-310 

Coal, a large lump of 297 

How combustion is produced 291 

Steam 151 

Fields, the world's 174 

Coins of Different Countries 172, 173 

Colors, suggestions for 441 

Combustion, spontaneous 136-139,297 

Spontaneous, liable to 291 

Compass— Why it varies 227 

Conductors (electrical) 535 

Copper, deoxidized 217 

Production of 170 

Tenacity and loss 336 

Weight of sheet 196-197 

Corliss Engine Valves, how to adjust 27 

Counter-boring, Tool for , 311 

Crystallized Tin Plates 373 

Cubic Measure 355 

Oube Roots, tables of , 107-11*" 



3 

Damper, oval, iow to make, 400 

Deafness Caused by Electric Lights 297 

Deep Soundings near Friendly Islands 414 

Decimal Equivalents 187 

Equivalents for inches, feet, ounces, pounds, etc... 442 

Dies, metal working , 326-33 1 

Dry Rot in Timber ., 429 

Dynamo, the; how made and how used.. 478-531 

What a Dynamo is; Faraday's Discovery 478 

How to make one; the Galvanometer 479 

Permanen t Magnets 481 

Testing the Galvanometer 482 

Experiments with one 483 

Experiments with a Magnet 48& 

The Magnet Poles; Currents produce Magnetism. 486 

Ampere's Rule 487 

The First Dynamo 488 

Clarke's Dynamo 489 

Function of the Commutator 490 

Hjorth's Dynamo , *. 492 

Siemens' Armature 493 

Currents not Continuous 494 

Magnetism produces Heat 495 

Pacinotti's Ring Armature 496 

Patterns for a Dynamo .497 

Pattern for Armature ..' 498 

Drawing for Armature 501 

Patterns for Field Magnets ..500-503 

Patterns and Drawings for Standard 504 

The Castings 505 

Assembling the Castings 506 

The Bearings 510 

The Commutator ...., 513 

The Driving Gear 516 

Wiring the Dynamo : Wiring the Armature 51 P 

Wiring the Field Magnets 52'o: 

Attachment of Wires 52a 

The Brushes „ 526 

Binding Screws and Connections 528 

The Complete , 531 

Management of the , , 532 

Novel 164 

Eccentric, How to set a locomotive 89 

Economy in f he Use of Injectors 131 

Eiffel Tower, the » 437 

Elbow, to describe a pattern for a four-piece 383 

Elbow Angles, table of height. 380 

Electrical Measurements 538 

Electricity Developed by Chemical Action 535 

Simplified 533 

Frictional; negative; positive 534 

Voltaic and galvanic 535 

Whatisit? , 535 

Electric Batteries (see Batteries) 53() 

Experiments 536 

Hand Lantern 242 

Heating 20- 



Electric Light; largest in the world 476 

Locomotive 19 

Machine 535 

Electro-Magnetism 486 

Emery Wheels, value of 273 

Engines (see Steam Engines) 23 

Comparative economy of high and low speed 116 

Manipulation of new 167 

Triple expansion 168 

Engine, Steam, use of Indicator. 30- 44 

Engineers, a warning to ... 189 

Pointers for 169 

Valuable information for.... ..... 161 

Experiment, an interesting 319 

Explosion of Hot Water Boiler 391-394 

Expansion of Substances by Heat 206 

Eve Trough, making 379 

Feed Water Heaters 84 

Ferrules, how to draw 305 

Figures, valuable 448 

Filter, a cheap 368 

Fire Grate Surface, rule for finding 47 

Firemen, rules for 140 

Fire Proofing Wood Work 440 

Flange Joint, how to make a strong 122 

Flaring Articles with Round Corners 376-379 

Flaring Oval Articles, pattern for 375-376 

Flash-Points of various Hydro-Carbons 277 

Floor, how to make a 425 

Floors, how to wax 338 

Painting 430 

Painting and varnishing 456 

Flower Stand, a wire 385 

Foaming in Boilers 144 

Forests of the United States 423 

French Cubic Measure 355 

Square Measure 357 

Weights. , 356 

Friction of Water in Pipes 55 

Fuel, heating powers of 211 

Furnaces, facts about 461 

Galvanic batteries ; galvanic electricity 536 

Galvanometer, the 479-483 

Gamboge, how prepared 226 

Gauges, steam 146 

Gear Teeth, how to prevent breaking 269 

Gearing, high speed 290 

Geometry, practical, for mechanics 98 

Glass Cutting by Electricity 296 

Glass, flexible 237 

Glass, frosted 448 

Glass, how to perforate 289 

Glossary of Technical Terms 545 

Glue for Damp Places 426 

Glue, on the use of, Glue Paint for Kitchen Floors 436 



Granite, polishing , 342 

Graphite, in steam fitting 141 

Grindstone, how to make a small 79 

Quarries 344 

To find weight of 42:i 

Gun Barrels, browning them 297 

Guns, large ones made 296 

Hand-hole Plates 145 

Heat, amount of, required to melt wrought-iron 268 

Divisions of degrees of 160 

Expansion of substances by 206 

Produced by Rapid Magnetization 495 

-proof Paints 408 

What is latent heat? 157 

Heating and Ventilation 386-390 

Power of Fuel 211 

Steam 154 

Steam m. hot water 462-464 

Surface of Boilers 47 

Surface, steam radiators 369 

High-speed Gearing 290 

Hip Bath in Two Pieces .406, 407 

Horse-power, nominal, indicated, effective 142 

of Steam Boilers 46^ 47 

of Steam Engines 23, 130 

Horses, strength of 458 

Hot Water Systems 368 

How to Cast a Face 284 

Hudson Bay Company 344 

Ice House, how to build 444 

Making, artificial 174 

Ice, Strength of 422 

Incrustations of Steam Boiler 146 

Indicator, Steam Engine 30, 42 

Description 30 

Method of indicating 31 

Driving rigging 32 

Diagrams 34 

Uses of 35 

Tables for 39 

Taking diagrams 40 

Special instructions 41 

Computing horse-power 42 

Injectors, economy in the use of 131 

How to set up; Suggestions regarding 53 

Insulators (electrical) 535 

-Iron and Steel, average breaking strain 159 

Making in India 275 

Iron Brick . . . : 428 

Castings, facts about 235 

Castings, how to bronze 336 

Combustibility of, proved 271 

Different colors, caused by heat 305 

Flat-rolled, weight by foot 198-203 

How it breaks 272 

in the Conoco 296 



Iron, Russian slieet • . • f ^ J 

Nevrmef hod of bronzing 47d 

Painting of *JJ-J 

Removing rust •■• -^r 

Weight and areas of , rS?'} R^ 

Weight of sheet .-. ,...196, 19/ 

Isinglass, facts about ^^ 

Ivory Gloss, how to put on wood '^d» 

Japanese Lacquer for Iron Ships 295 

Japanese Water Pipes • • -^-^ 

Lap on Slide Valves ':^5 

Lathe, how to gear for screw cutting ii^ 

Tools for metals ]^ 

Lead, ancient use of ^^Y 

on Roofs and in Sinks ^;^i 

Pipes, caliber and weight o6^ 

Leather, making japanned ^1° 

Lightning Rods, uselessness of ^^f 

Liquid Air • , Yqq 

Fuel Burners ^°^ 

Fuel, precautions to be taken m using 41/ 

Hydrogen , . • ^l^ 

Locomotive, an experiment with a J go 

Eccentric, how to set a ^^ 

Gas for 165 

Long Measure « 2 yS 

Lubricating without Oil 2^7 

Lumber Measurement Tables * / / 

Machinery, care of 1|^ 

Magnetic Poles, north and south 4»u 

Magnetism 5g2 

Effect on watches ° 2^2 

Faraday's discovery :••••••• • \^":"'-' la- 
Magnetization or Demagnetization Produces Heat 49o 

Mahogany, value of ^^^r 

Malleable Iron, to tin YeV 

Manilla Rope Transmission ^^^ 

Manufactures in the United States ••••••; ^^ 

Mathematics, definitions and useful numbers in 91 

Measures of Different Countries i^^ 

Measurements, electrical ^^^ 

Mensuration oc^ 

Metals, melting points of ^%% 

Value of 

Metrical and Centigrade'Equivalents 2 83 

Mica, uses of ^9? 

Mineral Wool ikVl^i 

Mitering, perfect ^*^ ^g^ 

Miter, to describe a x%i 

Molders, a valuable point for.... .^ ..;.;. i'A--;-' , 

Monetary Units and Standard Coins of Different Coun^ (^^^ 

tries .....••......••.••••••••••••.•••*•*.*** -. QQ 

Morse Code iSX 

Mortar Making "Jf ' 

Mud Drums, pitting of ,. ^^^ 



'/ 

Nails, Ten-penny ; what a pound will do , 427 

Number of, in a pound 337 

Natural Gas, use of, in cupolas 284 

Nickel Plating 226 

To polish 374 

Non-conductors (electrical) 535 

Novel Drawing Instrument 403 

Nuts, square number in a keg 268 

Hexagon, number in keg 26i) 

Oak Lumber, cars of 339 

'Of Course," for engineers., 26 

Ohm, the (electrical) 538 

Oil and Coal Buying „ 317 

Old Tins no Longer Useless 371 

Open Circuit Batteries (el ectrical) 53« 

Oval Damper, how to make 40") 

Oval of any Length, how to strike 385 

with Square and Circle o . . 398 

Paint, a durable black 407 

A valuable preservative < .. . 180 

Heatproof 408 

Work 418 

Painting Floors 430 

Paper Holder, an ornamental , 386 

Paper-Makers, valuable points for 417 

Patterns for a Dynamo 497-505 

How to mend 286 

Pattern for Tapering Square Article 404 

for a T Joint 402 

Making, hints on , 239 

Making, notes on - 318 

Pavements 447 

Pipes, cold water supply 431-434 

Cast iron, weight of 410 

Lead, caliber and weight 334 

Steam, a non-conducting coating for 134 

To find amount for heating buildings 434 

How to thaw out frozen 126 

Testsof steel 310 

Plane Iron, how to sharpen a 340 

Planing Machine, a novel 221 

Plaster, a new wall » 446 

for Moldings 457 

Plastering, estimating cost of 413 

Plating, gold and silver 23 

Power, transmitting 136 

Animal 122 

Pressure, atmospheric mean 55 

Primary Batteries (electrical) 536 

Principles of Boiler Construction 148 

Proposed Great Engineering Feat 435 

Proof of the Earths Motioii , 227 

Proportions for Steam Boilers 1H6 

Pulleys, rule for width and diameter 82 

Pumps for Supplying Boilers (see Steam Pump) 54 

Pumice Stone, how made 266 



8 

Pattern Making, notes on 3^ 

447 

Pavements 

Pipes, cold water supply 431-434 

Pipes, cast iron, weight of ^^° 

Pipes, lead, calioer and weight 334 

Pipes, steam, a non-conducting coating for i34 

Pipes, to find amount for heating buildings 434 

Pipes, how to thaw out '^ 

Pipes, steel, tests of ^i 

Plane Iron, how to sharpen 34^ 

Planing Machines ^^' 

Plaster, a new wall ^"^ 

Plastering, estimating cost of. 4i3 

Plaster for Moldings ^^57 

Pointers for Success in Business • • 55^) 

Poles, the magnetic " * " ^° 

Power, transmitting by vacuum • • ^^ 

Pressure, atmospheric mean 55 

Primary Batteries (electrical) 53 

Principles of Boiler Construction ^4 

Proportions for Steam Boilers *. ^^^ 

Proof of the Earth's Motion ^^7 

Proposed Engineering Feat "^35 

Pulleys, rule for width and diameter 82 

Pumps (see Steam Pump) 54 

Pumice Stone, how made 

Rails, steel ^-° 

Railroads, consumption of coal » 43° 

Railroads, electric, in Japan 325 

Railroad, electric, largest in country 282 

Railroad Signals ° ' ^ ^ 

Railway Gauges of the World ^7° 

Railway Transit, rapid ' • ^34 

Redwood Finish ^ 

Reservoir, tapering, round-cornered one 4oi 

Rivets, boiler, number per 100-pound keg 336 

_^ . , . 204 

Rivets, weight ot 

Rock, cost of excavating - . . 42 

Roof Framing, hip and valley -455 

Rope, how to select ^^3 

Rope, length per coil, and weight 2»» 



9 

Rails, steel 350 

Railroads, consumption of coal 430 

Railway Transit, rapid 134 

Red wood Finish 446 

Reservoir, tapering, round-cornered 401 

Rivets, boiler, number per 100-pound keg 336 

Weight of 204 

Rock, cost of excavating 428 

Roof Framing, hip vallej^ 455 

Rope, how to select 293 

Length per coil, and weight 288 

Rot in Timbers, dry 429 

Rule, General, for all classes of boilers 49 

To determine lap on steam side slide valve 25 

To find Area Steam Piston of Pumps 56 

Capacity of water cylinder of pumps 56 

Diameter of cylinder for required horse- 
power 24 

Diameter pump cylinder 55 

Height for discharging given quantity of 

water 51 

Fire grate surface of boiler 47 

Fire grate surface of locomotive boiler 47 

Heating surface of boiler 47 

Heating surf ace of locomotive boiler 47 

Horse-power of boiler 46 

Horse-power of locomotive boiler 47 

Indicated horse-power of engines 24 

Horse-power for eleva ting water 56 

Quantity of water to be discharged 56 

Quantity of water elevated . 55 

Pressure of a column of water 54 

Size orifice to discharge given quantities 

of water 56 

Rules for Firemen 140 

Rules and Regulations for Properly Wiring and Install- 
ing Electric Light Plants 539 

Moisture danger 539 

Earth danger 540 

Consulting engineer 540 

Conductors • 540 

Sectional area 540 

Accessibility 540 

Insulating 540 

Maximum temperature 640 

Distance apart 541 

Inflammable structures 541 

Metallic armor 541 

Joints 541 

Gas and water pipes 541 

Overhead conductors 541 

Lightning protectors 541 

Insulation resistance 542 

Switches; Main switches; Switchboards 542 

Construction and action 542 

Insulating handles 642 

Electrical fitting 642 

Cut-outs; Imperative use of 543 



Rope Transmission in England 4 

Rot ia Timbers ._ 43 

Rule to find area steam piston of pumps 56 

Rules for Belting: 

To find length and width 80 

To calculate horse-power. 82 

To find width of pulley,.., 82 

To find diameter of pulley , 82 

To find number of revolutions. 82 

Rule— To find capacity of water cylinder of pumps 56 

Rule— To find diameter of cylinder for required horse-power. 24 

Rule — To find diameter pump cylinder 55 

Rule— General rule for all classes of boilers 49 

Rule— To find height for discharging given quantity of water. "5 1 

Rule— To find fire grate surface of boiler 47 

Rule— To find fire grate surface of locomotive boiler 47 

Rule — To find heating ^lurface boiler 4.7 

Rule — To find heating surface of locomotive boiler 47 

Rule— To find horse-power of boiler 46 

Rule — To find horse-power locomotive boiler 47 

Rule — To find indicated horse-power of engines 24 

Rule— To determine lap on steam side slide valve 25 

Rule — To find horse-power for elevating water 36 

Rule— To find quantity of water to be discharged 56 

Rule— To find quantity water elevated 55 

Rule — To find pressure of a column of water , 54 

Rule — To find size orifice to discharge given quantities water 56 

Rule for Firemen % 140 

jEUiles and Regulations for Properly Wiring and Installing 

Electric Light Plants 53P 

Moisture danger •••••••• •-••.. S99 

Earth danger -• - S4o 

Ignorance, etc uo 

Consulting Kng^eer ^ S4o 

Conductors • 54o 

Sectional area 54C> 

AoT'^'ssibility • 54^ 

Insularly '>'.«. 540 

Maximum teu-'>^rature 540 

Distance apart •..*,.«,.• »»jf«54I 

Inflammable structures 541 



II. 

Metallic armor... o »,..<,.... o.... = co„o,<. » » 541 

Joints ...... o , ... o CO... o .., o ..... o . o o , . . . . 541 

Gas and water pipes 541 

Overhead conductors. . ................. ............ .0 ..... . 541 

Lightning protectors ... = ...... 541 

Insulation resistance • 542 

Switches «... — 542 

Construction and action. 542 

Insulating handles ........... . — ... 542 

Main switches. .......................... ............. 542 

Switch boards ....................... ^ -....., . .... 542 

Electrical fitting.... .».. ..o. ............................. . 542 

Cut outs 543 

Inoperative use of. ...... o ...... ^ ................ . ..... 543 

Situation. .. o c ..... o c c o o o . o . c . o .. o o o .... o o ........ o . o o ,,,, . 543 

Portable fittings. .... .o. <,,«>,.. o .... ....... = .....,,,, 543 

Arc lamps .... ,,,0 ..<.<, 0.0 ...o o o .................. ....»,.. . 543 

The dynamo .» o o.o, o ..» 00. o o . o = ......, ..... c ........ . . » . . « 544 

Batteries. .... oo , .0 o,.,oo ............... ....c ....oo.. ....- 544 

Maintenance .......... ...................... .... o,,,. .0, o . 544 

General. .......... o.. ......,..» 544 

Rust, how to remove from iron ,0=, ... ........ ....... . 222 

Rust-Proof Wrapping Paper. ,.,....., .... .... ....... ..o ........ , 406 

Rusty Steel, to clean. ...... 00 .....oo.o.cooo.o..ooc.o».,«=,.... 238 

Safety Valves .o...,o.......o.oooooo.ooo«oo.o...... .49, 50 

Safety Valve, rule for weights ......... o ...» o . .o .o o .. 00, o ....... . ng 

Saturated Steam, properties of, ..0..... co.,.co o...... .......... . 150 

Screw Auger, inventor of .............. ....... oo. ............... . 405 

Screw Ctitting, how to gear a lathe for. ....... c ............... o . <,• no 

Screw Drivers, an Improved ......... o ................ .......... . 229 

Screw Heads, how to bury out of sight .......................... 455 

Screw Making at Providence .298-300 

Screw Threads, table of gears for cutting. .................. .243-264 

Sea Water, action of on, cast iron piles,.... . 00 <,..oc..... ........ . 210 

Watch, facts about .....000.0000........ 325 

Shafting, accidents by ................ ... ... o ... o o o o o .......... . 130 

Shafting, an easy way to level . . . ^ ...... o . o «« o o o .,« ....... . ..... 307 

Shafting, belting at right angles .„o... .,..000004000.0000. 306 

Shafting, things to remember. ....ooooo.oo.ooooeoooo.ooo. 0.0.320 321 

Sheathing ce-llulold . ,^.,.o.......ooo.oooo..ooooooo.«oo.o...o.o.. ^35 

Shingles, to calculate number oil. ooe.oooo...oe3ooeo»ooo.. 00.000. 44^ 



12 

Situation 543 

Portable fittings 543 

Arc lamps 543 

The djl^namo 544 

Batteries 544 

Maintenance 544 

Rust, to remove from iron 222 

Rust-proof Wrapping Paper 406 

Rusty Steel, to clean 238 

Safety Valves 49, 51 

Safety Valve, rule for weights 119 

Saturated Steam, properties of 150 

Saw-Mill Operated by Air 185 

Screw Cutting, how to gear a lathe for 110 

Driver, an improved 229 

Heads, how to bury out of sight 455 

Making at Providence 298-300 

Threads, table of gears for cutting 243-264 

Sea Water, action of, on cast iron piles 210 

Shafting, accidents by 130 

An easy way to level 307 

Belting at right angles 306 

Things to remember about 320, 321 

Sheathing, celluloid 135 

Shingles, to calculate number of 447 

Shop Kinks, useful 395-398 

Signals, railway 183 

Sleepers Used by World's Railroads 409 

Slide Valves 24 

Setting of.. ■.... 87 

Smoke, how formed. 156 

Soda A.sh in Boilers 438 

Solder, cold 370 

Soldering 470, 472 

Soutii C?.^olina Cotton Industry 13 

Specific Gravity, weight and strength of metals 416 

Square Measure 357 

Square Roots, table of 107-110 

Steam as a Cleansing Agent 1^8 

An invisible gas — 126 

Steam Boilers, analysis of incrustations loC 

Boiling 145 

Blowing off under pressure 152 

Care of 45 

Calking 124 

Cleaning tubes 155 

Foaming 144 

Hand-hole plates 145 

Horse power of 46 

How plates are proved , 179 

How to prevent accidents ... 147 

How to test 162 

Important to those operating 147 

Incrustations of 146 

Kinds of 45 

Law of proportions 160 



\ 

\ Steam Boilers, Marine 47 

Mistakes in designing 158 

Principles of construction 148 

Proportions for * 166 

Rules for 47, 53 

Safe working pressure flues 184 

Testing plates 166 

The total pressure 152 

Treatment of ., 115 

Tubular 47 

Steam Coal 151 

Steam Engine, The 23 

Comparative economy high and low speed 116 

Corliss valves, how to adjust 27 

Expansion by lap , 25 

Horse powers— actual, indicated, nominal.. '^3, 142, 143 

Indicator 30, 42 

Manipulation of new 102 

Mean pressure in cylinder 23 

Rules 23, 25 

Slide valves 24 

Slide valves, setting of 87 

Theory of the y. . 112 

Steam Fitting, use of graphite 141 

for Heating 58 

Gauges 146 

Heating 154 

Radiators, heating surface of 369 

Pipes, for heating buildings 434 

how to thaw out 126 

Properties of saturated 150 

Pumps, suggestions 54 

to find diameter cylinder 55 

to find quantity water elevated 55 

Super-heated 146 

vs. Hot Water Heating 462-464 

Steel, chemical or physical tests for 212 

How to anneal 223 

Notes on working of 267 

To clean rusty 238 

Pipes, tests of 310 

Punches, tempering 208 

Rails, used as girders 35G 

Rules, how they are made 211-212 

Sheet Pavements 22 

Sleepers, rivetless 184 

Square, how to use 372 

Suggestions to workers 213 

The secret of cast 274 

Weight of sheet 196, 197 

When hardened 139 

Why hard to weld 304 

Stone, natural and artificial 365 

Crushing strength 365 

Storage Battery, how to make one 312 

Strainer, rain water 399 

Strength of Materials 359-361 

Switching from an Engine Cab 183 



14 

Submarine Cables ....o.. 278 

Superheated Steam .,., 146 

Surveying Measures 358 

Sycamore 439 

Tables:— 

Alloys 186 

Chimneys 90 

Heating surface per horse-power 48 

Cube and square roots 107-110 

Density of water 123 

Diameters, high and low pressure Cylinders 122 

Difference of time from New York 180-182 

Friction of water in pipes 55 

Horse-Power transmitted by belts 120, 121 

Lap according to travel of slide valve 25 

Length and number of tacks per pound 182 

Proportions cylinder tubular boilers 48 

Properties of saturated steam 150 

Safe working pressure for iron boilers 153 

Safety-valves, capacity of 51 

Size and capacity of standard pumps 57 

Saving by feed water heater 86 

Specific gravity 160 

Square and cube roots 107-110 

Strength of belting material 83 

Tacks, length and number per pound • 182 

Tanks, how to calculate capacity of 335 

Taps, universal, table for making 265, 266 

Telephones 132 

Temperature, indicated by color of flame 49 

Tempering Steel Punches , 208 

Testing Boiler Plates 166 

Testing Exterior Stains , 444 

Tests for steel, chemical or physical 212 

Thermometers, how made 300 

Thermometer Scales 302, 304 

Thermal Unit, explanation of 155 

Theory of Steam Engine 112 

Things That Will Never Be Settled 293 

Worth Knowing 294 

Timber, a colosal stick of 457 

dry rot in , 429 

in favor of small 343 

properties of 366 

rot in 438 

seasoning 435 

specific gravity and strength of 417 

Time, difference from New York 180-182 

Tin, Modern uses of 466-468 

Plate, crystallized 37 3 

endless 373 

Production of 170 

Sizes and weights of 333 

Tinning by simple immersion 434 

Improved process of 469 

Tool for counter-boring 311 

Tools in daily use 17b, 215 



lb 

Tools, how to anneal small 187 

How to detect iron and steel 173 

How to keep '229 

Tracing Paper, how to make 208 

Traction, influence of roads and weather 74 

Trees, the annual ring in 419 

Tubes, solid drawn , :224 

Tu-ningor Lathe Tools for Metals 77 

Underground London 22 

Universal Taos 265-266 

Useful Cements i;i4 

Useful Numbers and Definitions 91, 315-317 

Useful Receipts 374 

Useful Shop Kinks 395-398 

Vacuum, transmitting power by a , 136 

Valuable Figures 448 

Varnish, to make it adhere to metals 282 

Removal of old 441 

Varnishing and Painting Floors 456 

Ventilation and Heating. 386-390 

of Buildings 451-454 

Hints on 422 

Vibration how to overcome -. 185 

Volt, the (electrical) 538 

Voltaic Electricity 536 

Wages in Two Countries 1 64 

Wastes, Kitchen and Table Ill 

Watch as a Compass 290 

Watch and Learn 216 

Watches, effect of magnetism upon 230 

Watch, facts about 325 

Wheels, number of revolutions of 283 

Water and Pumps 170 

Curtain, a 23 2 

Density of 123 

Fresh 170 

Friction of, in pipes 55 

Salt , 170 

Simple tests for 294 

Useful information about 54 

Pipes, Japanese.... 210 

Weight, avoird tipois 356 

of Animals 165 

of Bolts per 100 207 

of Copper 196,197 

Cast Iron per lineal foot . 205 

Cubic loct of substance 340-348 

of Fuels 165 

of Iron 190-203 

of Rivets and Round-Headed Bolts 204 

and Specific Gravity of Metals . CC^ 

of Sheet Brass 196, 197 

of Sheet Steel 196, 197 

Weights, French 356 

of Metals, useful numbers for 418 



i6 

"Welding, Various Processes • 17, 17a, 370 

Wells, artesian 344 

Wesiinghouse Automatic Brake— Description 59 

Air Pump 61 

'I riple valve 63 

Westinghouse Automatic Brake-Engineer's brake-valve 65 

Pump g:overnor 67 

Equalizing valve 65 

IiistructioDS 69 

How to apply— how to release 71 

Brake power 73 

Car levers , . 74 

Wh^ii a day's work begins 289 

Window Glass, how large cylinders are cut 344 

Number of lights in a box of 50 feet 270 

Wire Manufacture, new process 409 

Wood, a polish for 447 

A very durable 443 

Preservation by lime ' 443 

Woods, tensile strength of common 208 

weight of 333 

Wooden Beams, safe load for 345 

Workshop Jottings 322 

Wrapping Paper, rust-proof 406 

Zinc, as a fire extinguisher 381 

How to polish 424 

Production of 170 



COTTON INDUSTRY IN NORTH CAROLINA. 

In i886 this state had 8o cotton mills, 4,071 looms and 
199,433 spindles. In 1894 this had increased to 156 mills, 
with 14,908 looms and 700,497 spindles. 

In 1897 has been witnessed a wonderful increase in cot- 
ton manufacturing, for there are now in this state 1,010 
cotton mills, with 1,410 knitting machines, 24,517 looms 
and 1,044.835 spindles. 

The average daily wages paid skilled men (exclusive of 
machinists, engineers, firemen and superintendents) $1.11; 
unskilled, 66^ cents; skilled women, 67^ cents; unskilled, 
46 cents, and children 34^ cents, or a general average of 
65 cents a day. 

The prospect for a rapid extension of the cotton mill 
industry is excellent, for within the state are water courses 
with an aggregate of 3,500,000 horse-power, capable of 
running 140,000,000 spindles. 

Here is the cotton grown and its transportation to the 
northern mills saved by its manufacture here. The mills 
are in excellent condition, and some are declaring as high 
as 15 per cent, dividend on the capital invested. 



MECHANICS' 

COMPLETE LIBRARY 



ELECTRIC WELDING. 

The process of electrical welding consists of pressing 
the two pieces of metal firmly together and passing 
through them a heavy current of electricity at a low 
voltage. The metals almost immediately reach a high 
temperature at the point of juncture, and weld together. 
The heat is developed at the point of juncture and not 
elsewhere, for the reason that by far the largest share 
of the resistance is found at this point, resulting in the 
production of heat according to well-known electrical 
laws. This localization of the heat is one of the great 
advantages of electrical welding, as it is thus possible to 
make welds heretofore considered impossible — as for 
example, the welding of a tungsten tip on a steel spring 
without destroying its temper. High speed steel to low 
carbon steel — steel to brass or bronze — malleable iron 
to steel — vanadium, tungsten, nickel, and nickel-chrome 
steel — all these can be welded successfully by electricity. 
One and two throw-crank forgings are welded so as to 
make three, four, and six throw-crank shafts. The 
strength of the ordinary electric weld varies from 75 
to 95 per cent of the original piece, but can easily be 
made to run above 1 00 per cent. Standard electric 
welding machines are now on the market designed for 
all classes of work. These machines consist primarily 
of clamps to hold the stock firmly together while hot, 
and means to provide a large volume of current at a 
low voltage. The current is almost universally obtained 
from an alternating current transformer having but one 
turn on the low side. The electric method of welding 
effects great saving in manufacturing costs where many 
welds of the same sort are to be made. 

For Russian method of welding see page 3J0, 
17 



I7a 

OXY-ACETYLENE WELDING. 

Autogenous welding with the oxy-acetylene flame is the 
process of causing two parts or pieces of the same or 
different metals to flow together under extreme heat in a 
melted state, forming one solid piece when cooled. 

The temperature of 6,300 degrees Fahrenheit used in this 
process is generated by the burning of two gases, oxygen 
and acetylene, in certain definite proportions. The two 
gases are led through tubes to the welding torch, this torch 
consisting of a mixing chamber and a suitable nozzle or jet 
at which the flame appears. Built into the torch are two 
valves by means of which the operator controls the mixture 
and, to a certain extent, the heat and action of the flame. 

The gases are secured from special generating machines 
or may be drawn from steel cylinders filled with gas under 
compression. Attached to the generators or cylinders are 
regulating valves which control the pressure of the oxygen 
and of the acetylene flowing into the tubes. 

The oxy-acetylene flame will melt practically any known 
material, its heat being more than twice that at which the 
hardest metals melt. The process is used in the manufac- 
ture of new articles which require seams or joints and in 
the repair of broken or cracked metal parts. The joint 
made is so perfect that it cannot be distinguished when 
smoothed after the weld. 

To prevent the formation of scale or gases at the joint 
during welding, materials, known as * 'scaling powders" or 
"fluxes," are used. Fluxes are made from borax, salt and 
various chemicals, the flux varying with the material to be 
welded. Additional metal is added to the joint by melting a 
sufficient quantity from a rod held by the operator, the rod 
and the edges to be united being made to flow simultaneously. 

The pieces to be welded are cleaned at the edges and 
are usually beveled in such a way that the flame can reach 
every part of the edge. Heavy parts are held in place by 
suitable rests or clamps and are placed to allow for the 
contraction of the metal when cooling. Cast iron and 
aluminum require that the whole piece be heated before 
welding, thus uneven contraction and resulting breakage 
are avoided. Unless especially treated after cooling a 
welded joint has not the same strength as the original 
piece. This is overcome by adding metal to the joint, 
making it slightly thicker than the part itself. 



1 7b 

RULE TO TEMPER TOOLS USED DAILY. 

Tempering is the process used to make steel cutting 
tools tough enough to hold their edge after hardening. 
Tempering steel makes the grain finer and adds greatly to 
its strength. The steel is first hardened by heating red 
hot and cooling more or less quickly. The degree of hard- 
ness depends on the rapidity with which the metal is 
cooled. Cooling is usually accomplished by dipping in 
water, although for securing extreme hardness, brine or 
mercury may be used. Oil used for cooling gives tough- 
ness without extreme hardness. 

To temper flat, cape or side chisels, and common flat 
drills, put the tool to be tempered in the fire and heat 
slowly to a cherry-red color, about four inches from the 
point. Then take it out and put it in the water, point first, 
about three or four inches, then draw it back quick about 
an inch from the point, and leave it so until the water will 
barely dry on the chisel, then take it out, polish it with a 
piece of sand stone, and let the heat that is left in the body 
of the tool force its way towards the point; it will be 
noticed immediately in the change of color. The color of 
temper for chisels to cut cast iron should be dark straw, 
turning to a blue. The temper of chisels to cut wrought 
iron or steel should be plunged into water after the dark 
straw color has disappeared and the blue begins to show 
itself, and left in the water to cool off. In some cases, 
where the tool is too cold and the temper will not draw, 
put the tool in and out of the fire often, until the temper 
shows itself, then cool immediately. If the temper gets to 
the point of the tool before it is polished, it will have to be 
heated over again. The above ru^e answers for lathe, 
planer and shaper tools as well. 

Taps, dies, reamers and twist drills should be tempered 
in oil. After being heated to a cherry red all over equally, 
drop the tool into a bucket of oil (plumb) and leave it 
there until cold; then take it out and brighten it with 
emery cloth; be careful not to drop it, because it is brittle 
and liable to break. To draw the temper of taps, reamers 
and twist drills, heat a heavy ring red hot and enter the 
tool centrally in the ring, so the heat will be equal from all 
sides. The hole In the ring should be about three times 
the diameter of the tool. An old pulley hub would be 
about right. The color for reamers, taps and twist drills 



lb 



L- 




P 










O B 












to \ 


V 


S % 




3 Un 






=: 


a m\ 1 


: 












g; 




W 




2 MACHINISTS 


H SQUARE. 




TOOLS IN COMMON USE. 



19 

should be dark straw, turning to a blue near the shank; 
where the color is changing too fast, drop a little water on 
it; after the right color is obtained, cool off in water. To 
draw the temper in dies after being cooled in oil, set them 
(the threads up) on a piece of red-hot iron and draw tem- 
per the same color as taps. 

For tempering a spring, heat it cherry-red and put it in 
oil; after it is cool, take it out and hold it over the fire 
until the oil burns off; then put the spring in the oil again, 
the in the fire; do this three times; after the last time, 
plunge it into water and cool off. 



ELECTRIC LOCOMOTIVES. 

The Baldwin and Westinghouse electric engine has 
solved the problem of a locomotive running 120 miles an 
hour. 




In appearance this new wonder does not betray its qua- 
lities. The motors are incased, so that hardly any mechan- 
ism is in sight. The electric headlight and the pilot alone 
disclose its character as a motor car or locomotive. 

The locomotive weighs 150,000 lbs. and is 37 feet long 
over the pilot. 

The frame is made of lo-inch rolled steel plate over 
the entire floor, giving enormous strength to resist blows in 
collisions, etc. 

This frame is carried on two trucks, with all the modern 
devices of springs, for swinging motion and free movement. 
The trucks are built very strong and they are of the swivel- 
ing type, so they may go around any curve passable for an 
ordinary freight car. 

The geared connection between the axles and the elec- 
tric motors permits of any gear racio desired. 



The driving wheels may be connected by parallel rods 
for pulling heavy trains, as such rods would not permit one 
pair of wheels to slip without the other. 

The motors are directly beneath the car floor, between 
the two trucks, and are * ' iron-clad ' ' consequent pole 
motors. They are entirely encased in thin steel shells, so 
as to be protected from all injury under normal conditions 
of service. 

The armatures are laminated, being made up of thin 
slotted discs of steel. In the slots the armature wires are 
placed. The commutators are of the best forged copper 
with mica insulation. The motors have the highest grade 
of insulation. Power is furnished by the third-rail system. 

At both ends is a controller. The path of the current 
may be divided so as to pass to both motors independently, 
or it may be sent through one motor to the other. 

^'iThe breaking system has some unique features. The 
compressed air-brake is used. The engineer's valve is of 
the standard Westinghouse type. When the handle of the 
brake valve is put at '* emergency" pneumatic action 
breaks the circuit at the same time as it applies the brakes. 
A special reversing switch acts on the motors. The auto- 
matic air pump is driven by electricity, its special motor 
being directly coiinected and without gear. 

The interior of this locomotive is that of an observation 
car, and very handsome. 

Our I20-miles-an-hour locomotive is ready for us, but 
we are not quite ready for it. Before we can risk flying 
across the country at such speed all grade crossings must be 
abolished and the whole present R. R. signal system must 
be changed. Signals are now about a mile apart, while 
the newlocomotive cannot stop within less than one and a 
half miles of clear way. 

ELECTRICITY FOR HEATING. 

To fit heating and cooking utensils for the use of elec- 
tricity, a thin film of enamel or cement is spread over the 
outer saucepan, griddle, kettle or heater. Then iron, plati- 
num or other high resistance wire is laid zigzag over it, with 
copper wire connections made to the two ends; and more of 
the cement or enamel is spread over the wires so as to com- 
pletely embed them. When enamel is used the apparatus 
is put in a kiln and burnt on similar to the ordinary iron 



21 



cooking utensils. In both methods the fil..n of enamel oi 
cement insulating the heating wires is put on so thni and is 
so good a conductor of heat that the heat generated by the 
electricity is rapidly conveyed to the utensil to be heated. 




CUlDDUi. 



CQEESBcHEAXEB. 



Electricity can thus be sent through the wires without fear 
of overheating them. This would not be possible it they 
were exposed to the air, which does not conduct heat but 
radiates it. 



22 

RECEIPTS FOR GOLD AND SILVER PLATING. 

Ail articles to be plated should be dipped in strong lye 
or diluted nitric acid, and rinsed ofi: with soft water; then 
place the article to be plated in the glass that has the solu- 
tion of either gold or silver, and take a couple of pieces of 
zinc I inch wide, and double to ^-inch wide, by lo long; 
let it touch the article to be plated, and you will be sur- 
prised at the result. This answers for both. 

Take a tablespoonful cyanide of gold and put it in a 
glass of water, to do gold plating. 

Take silver and dissolve in a glass with little nitric acid, 
when the silver is dissolved then drop hydro- chloric acid in 
until the white precipitates (silver chloride) ceases to fall; 
pour off the colored water after it has settled, and add soft 
water to it, then it is ready for use. 

STEEL SHEET PAVEMENTS. 
For certain structural purposes the combination of iron 
and steel with concrete has in various instances been suc- 
cessfully resorted to by builders. According to this method, 
a steel sheet of light guage is slit perpendicularly in short 
lengths, say three inches, these slits running in a straight 
line clear down the sheet, each new one beginning about 
half an inch from the point where the preceding one ended 
and the lines being about half an inch apart, this method 
leaving the sheet of steel cut into long strips of half an 
inch in width, but connected together every three inches or 
so. The sheet is now grasped by the same machines on 
two opposite sides and pulled apart or expanded, so that all 
the openings appear in diamond shape, the sheet really 
looking like a wire grating when ready for use. On the 
earth of the street graded into shape and bedded over with 
sand is placed the sheet of expanded steel, and over the 
steel is then laid a layer of concrete, this latter being so 
tamped into the meshes of the metal as to form a perfect 
bond. Upon this foundation can be laid asphalt, bitumin- 
ous rock, basalt block, brick or any kind of surface pave- 
ment desired. 

UNDERGROUND LONDON. 

Underground London contains 3,000 miles of sewers, 
34,000 miles of telegraph wires, 4,530 miles of water mains, 
3,200 miles of gaspipes, all definitely fixed. 



^3 

THE STEAM-ENGINE. 

The term " Horse-power " is the standard measure of 
power as applied to steam-engines. This unit of power has 
been adopted by all manufacturers of steam-engines in all 
parts o^ the world. 

The term originated with Watts, the so-called inventor of 
the steam-engine. He demonstrated that a horse could work 
8 hours a day continuously, traveling at the rate of 2% miles 
an hour, raising a weight of 150 pounds 100 feet high by 
means of a block and tackle. Reducing this to equivalent 
terms, a horse could raise 150 pounds at the rate of 220 feet 
per minute, or 2% miles an hour, or 33,000 pounds one foot 
per minute. Thus, a horse-power is the power required to 
raise 33,000 pounds one foot a minute. There are three 
kinds of horse-power referred to in connection with engines, 
''^ nominal^'''' '■'•indicated'''' and ^^acfz^ a I." 

The nominal horse-power is found by multiplying the area 
of the piston in inches by the average pressure, and multiply- 
ing this product by the number of feet the piston travels in 
feet per minute, then dividing this last product by 33,000. 
The quotient will be the nominal horse-power of the engine. 

The indicated horse-power is found by multiplying together 
tne mean effective pressure in the cylinder in pounds per 
square inch, the area of th^ piston in square inches and the 
speed of the piston in feet per minute, and dividing the prod- 
uct by 33,000. 

The actual horse-power i> the 'ndicated horse-power 
minus the amount expended inovercc mingthe friction. The 
following is a general rule for calculating the liorse-]:)ower of 
an engine: 

Rule. — Multiply the area of the piston in square inches^ 
the mean pressure of the steam on the piston per square 
inch^ and the velocity of the piston in feet per minute^ , 
together^ and divide this product by jj,ooo. The quotient 
will be the horse-power. 

The mean pressure in the cylinder, when cutting off at 

X stroke, equals boiler pressure x .597 



M 




(< 




X .670 


Ks 




(< 




X .743 


'A 




a 




X .847 


% 




(I 




X .919 


% 




I a 




X .937 


K 




( <« 


((. 


X .966 


7;. 




I <» 


(f ( 


X .Q92 



24 

TO FIND THE DIAMETER OF A CYLINDER OF AN ENGINE 
OF A REQUIRED NOMINAL HORSE-POWER. 

Divide 5,500 by the velocity of the piston in feet per minute, 
and multiply the quotient by the required horse-pov^^er. The 
product will be the area of piston in square inches. From 
this the diameter can be obtained by referring to table of areas 
of circles. 

TO DETERMINE THE EFFECTIVE POWER OF AN ENGINE BY 
AN INDICATOR. 

Multiply the area ot the piston m square mches by the 
average force of the steam in pounds; multiply this product by 
the velocity of the piston in feet per minute ; divide this last 
product by 33,000, and {'q of the quotient vi^ill be the 
eflective power. 

The travel in feet of a piston is found by multiplying the 
distance it travels in inches for 07ze stroke by the whole 
number of strokes per minute. Dividing this product by 12 
gives the number of feet the piston travels per minute. 

THE SLIDE VALVE. 

How to set a slide valve. — Place the crank at the center, 
and the eccentric at right angles with the crank; then put 
the valve in the center of its travel, and the rocker plumb at 
right angles with both cylinder and crank-pin ; when this is 
done, adjust the valve-gear to its proper length, the^ move 
the eccentric forward until the valve has the desired amount 
of lead; make the eccentric fast in this position, and turn the 
crank around to the other center, and see if the lead is equal; 
if so, the engine will run all right. In case the lead is not 
equal, equalize it by moving the eccentric slightly back and 
forth. 

Where the lead is unequal on account of wear, the travel 
of the valve may be equalized by placing lines of brass or tin 
behind or in front of the box which connects the valve-rod 
with the rocker. The " outside lap '' means steam lap ; the 
" inside lap " means exhaust lap. 

To compute the stroke of a slide valve, — To twice the lap 
3,dd twice the width of a steam port in incheSj and the smri 
will give the stroke required. 

Half the throw of the valve should be at least equal to chfc 
lap on the steam side, added to the breadth of the port. li 
this breadth does not give the required area of port, the 
throw of the vaive most be increased until the required area 
is attained. 



By referring to the following tatle, the desired lap may be 
found if the travel of the valve is known: 





The travel of the p 


iston where the 


' steam is cut off. 


Travel of 


















the valve 


4 


-i 


3 2 


i 


ti 


2 
3 


4 


!S 


in inches. 






















The required lai 


• 






T 


3 


I 1, 


b 


^ 


1. 


I 


a 


2 


8 


4 


1 6 


,8„ 


if 


2 


IG 


f 


3 


;? 


I 


7 


I 


4 


i 

1 


I 


31 


I* 


I,^« 


i.^ 


i| 


'"'> 


I 


7 
8 


* 


% 


2 


iil 




1^ 




;t 


I 


8 


5 


2i 


2 


>fs 


I ft 


I ^ 


I 1 


li 


I 


51 


2l^« 


2,^« 


2 


III 


I f 


a 


I i ' 


li 


6 


2i 


2^6 


2 1^6 


2 


lii 


I? 


li 


1 1^6 



To find how much lap imist be given on the steam side of 
a slide valve to cut off the stea??z at any given part of the 
stroke of the piston. — From the length of stroke of the piston 
subtract the length of the stroke that is to be made before 
the steam is cut off; divide the remainder by the stroke of the 
piston, and extract the square root of the quotient; multiplv 
this root by half the throw of the valve; from the product 
subtract half the lead and the remainder will give the lap 
required. 

Expansion by lap^ with a slide valve operated by an eccen- 
tric alone, cannot be extended beyond one-third of the stroke 
of a piston without interfering with the efficient operation of 
a valve; when the lap is increased, the throw of the eccentric 
should also be increased. 

The lap on the steam side must always be greater than 
that on the exhaust side, and this difference must be in- 
creased the higher the velocity of the piston, for, in fast-run- 
ning engines, also m locomotives, it is necessary that the ex- 
haust valve should open before the end of tlie stroke of the 
piston, so that more time can be allowed for the escape of 
steam. 



26 

" OF COURSE " FOR ENGINEERS. 

Of course you will always start your engine slowly, so that 
the air and water condensation can be expelled from your 
cold cylinder; then you will gradually bring it to its regular 
speed. 

Of course you will be sure to keep open the drip cock, 
both in the front and back heads of the cylinder, when the 
engine is standing still, and never close them until all the 
water has dripped out. 

Of course you will never let in any oil or tallow to your 
cylinder until it is made hot by the steam. 

Of course you will be careful not to put in too much oil at 
any time, knowing, as you do, that it will be sent to the feed- 
water and cause your boiler to prime and foam. 

Of coiv/se you will always oil up before starting your 
engine. 

Of course you will always keep your piston and valve-pack- 
ing in a bag or clean drawer, so as to keep sand, dirt or other 
grit from becoming attached to it, and so cut or flute the rods. 

Ofcottrse you will not use new waste to wipe up the dirty 
oil from the stub-ends, crank-pins or cross-head guides, and 
then use the same waste to polish up the bright and finished 
work. 

Of course you will exercise great care in adjusting the 
packing in steam-cylinders. 

Of course you know that when you generally pack the 
piston packing, both cylinder and packing are cold, and if they 
are screwed or wedged in very tight while in this condition 
that the expansion, when exposed to the heat of the steam, 
will induce great rigidity. 

Of course you understand, if this is so, the oil or lubricat- 
ing substance cannot enter between the surfaces in contact, 
and that great friction, heating and cutting will be the result. 

Of course you are aware that when packing loses its elas- 
ticity it is no good, and should be removed. 

Of course you know that piston or valve-rod packing should 
never be screwed up more than sufficient to prevent it from 
leaking, and that the softer the packing the longer it will last 
and the better your engine will run. 

Of course you have tried that little trick of screwing the 
packing up tight when it is first inserted in the boxes, and 
then slacking the nut off to allow the packing to swell when 
exposed to the heat of the ste.m.. 

Of course you will read pages 53, 88, 90, 95, 97* and 103 in 
ihis book- 



HOW TO ADJUST AND SET CORLISS ENGINE 

VALVES. 

The original crab-claw valve- gear, as used by the inventor, 
Geo. H. Corliss, has been gradually superseded by the im- 
proved half-moon valve-gear, used on the Reynold's engine 
and other prominent Corliss engine builders. 

This difference between the old and new style of valve 
applies only to the steam-valves, as, in both cases, the ex- 
haust-valves open toward the center of the cylinder. 

In the Corliss valve-gear (sometimes called " detachable 
valve-gear ") the action of the steam-valves is positive, the 
direct action of the working parts of the engine opening 
them at the proper time, and keeping them open until the 
connection with the engine is detached or broken, and the 
hook tripped by the working of the cut-off cams. The steam- 
valves are closed by vacuum dash-pots (sometimes by springs 
or weights). The cut-off is automatic and is determined by 
the lequirements of the load on the engine, so that the cut- 
off cams do not always trip the hook at the same point, as 
they are moved by the governor. 

To those unfamiliar with the Corliss valve-gear, it ap- 
pears a very complicated affair, yet, in reality it is very simple, 
and is more easily adjusted than the ordinary slide-valve. 

To understand the simplicity of the Corliss valve-gear, the 
four valves (two steam, two exhaust), must be considered as 
the four parts — or edges — of the common slide-valve, that 
is, the working edges of the two steam-valves are equivalent 
to the two steam edges of the slide-valve, and the working 
edges of the two exhaust-valves as equivalent to the exhaust 
edges of the shde-valve. 

The principle is the same in the two styles of valves — 
Corliss and slide — but the difference comes in the adjustment, 
for the slide-valve is a solid valve, and any adjustment of one 
part affects the whole, while with the Corliss valve each 
part is susceptible of an individual and separate adjustment, 
which can be made, if necessary, while the engine is work- 
ing, without shutting down. The eccentric works the valves, 
and are connected with them on the Corliss gear, by means 
of the wrist plate, carrier-arm, rocker-arm and reach-roc? 

Besides imparting motion to 'he valves, the wrist-plate 
modifies the speed of travel at different parts of the stroke, 
giving a quick and accelerating speed when opening the 
steam-valve, and a quick opening and closing of the exhaust- 



ki6 

vaive, both stearr. and exhaust -valves being at their slowest 
speed when closed. 

First, remove the back-leads or back-caps of the fo'ir valve- 
chambers; when thiS is done the engineer will find guide hnes 
on the ends of the valves, and also on the ends of the valve- 
chambers. The lines on the steam-valve will coincide with 
the workmg edges of the valve, and those on the steam-valve 
chamber with the working edges of the steam-ports. Guide 
lines will also be found on the exhaust-valves and ports. 

The wrist-plate is located on the valve-gear side of the cylin- 
der, in a central position, between the four valve-chambers. 

On the stand, which is bolted to the cylinder, will be found 
a deeply scribed line, and on the hub of the wrist-plate, three 
other lines, which show the center of the wrist-plates, and 
the limits of its travel or throw. 

To adjust the valves, the reach-rod which connects the 
wrist-plates with the rocker-arm, must first be unhooked; next 
place the wrist-plate in its central position and hold it there. 

All the connecting-rods between the steam and exhaust 
valve-arms and the wrist-plate, are made with right and left 
hand threads on their opposite ends, and furnished with jamb- 
nuts, so that the rods can be easily lengthened or shortened 
by merely slacking the jamb-nuts and turning the rods. 

■ In this manner, set the steam-valves so that for every lo 
inch diameter there will be ]^ inch lap, and for every 32 
inch diameter ^ inch lap, other intermedi^.te diameters in pro- 
portion to these distances. 

Set the exhaust-valves for every 10 inch diameter of cylin- 
der with -^ inch lap, and for 32 inch diameter ^ inch lap. 
Double these distances for condensing engines. 

The lines on the valves which are nearer the center of the 
cylinder than the "lines on the valve-chambers show the lap 
on both steam and exhaust valves. 

After the valves have thus been adjusted, turn the wrist- 
plate to the extreme limits of its throw, and adjust the rods 
connecting the steam- valve arms with the dash-pots, so that, 
when the rod is down as far as it will go, the square steel 
block on the valve-arms will just clear the shoulder of the 
hook. The adjustments of these connecting rods must be 
properly made, for if too long the steam-valve arm will be 
bent or broken, and if too short the valve will not open, be- 
cause the hook will not engage. 

Now hook the engine in, loosen the eccentric on the shaft, 
and turn it over, adiustin;? tiie eccentric-rod so that the lines 



5*9 

on the hub of the wrist-plate, which show the limits of its 
travel and throw, will coincide with the line scribed ou the stand. 
Place the crank on iis dead-center, and turn the eccentric 
in the direction which the engine is to run, so that the steam- 
valve will show an opening of ^-^ to ^ of an inch (depending 
on the speed at which the engine is to run — the faster the 
speed the more lead it requires). The Ime on the valve, 
which is nearer the end of the cylinder than the line on the 
valve-chamber, shows the opening required, v/hich is the 
*' lead " or port opening when the engine is on its dead-center. 
Now secure the eccentric, or the shaft, by tightening the set- 
screw, and throw the engine over to its other dead-center, 
carefully noting if the other steam-valve shows the same 
opening or lead. If it does not, adjust it properly by length- 
ening or shortening the connecting-rod from the valve-arm to 
the wrist-plate. 

The exhaust-valves are adjusted in the same manner. 
The directions just given are for the half-moon style of valve- 
gears, which open from the center of the cylinder. In cases 
of the crab-claw, or any other style which open toivard the 
center of the cylinder, the method of adjustment is the same 
as given above; but, with the difference that the lap on the 
steam-valves will be shown when the line on the steam-valve 
is nearer the end of the cylinder, and the lead when the line 
is nearer the center of the cylinder than the line on the valve- 
chamber. 

In adjusting the rod connecting the cut-off or tripping 
cam with the governor, the governor must be at rest, and 
the wrist-plate at one extreme of its throw or travel. 

First adjust the rod connecting with the cut-off cam on 
the opposite steam-valve so that there will be ^^ inch clear- 
ance between the cam and the steel on the tail of the hook. 
Throw the wrist-plate to the other extreme of its travel and 
adjust the cam for the other steam-valve in the same manner. 
Now block the governor up i^ inch, which will be its 
average distance when running. Hook the engine in and 
turn it slowly in its running direction, and mark the distance 
the cross-head travels from its extreme position of dead- 
center when the cut-off cam trips the steam-valve. Continue 
to turn the engine slowly past the oiner dead-center, aiid 
mark the distance of the cross-head from its extreme of travel 
when the steam-valve drops. If the distance is the same in 
both cases, the cut-off is equal and the adjustment is correct. 
If not, adjust one or the other of the lods until this is so. 



3« 
THE STEAM-ENGINE INDICATOR 




The steam-engine indicator is now recognized as a higlil> 
essential device, with which every engineer should be familiar. 

The three main objects for which the indicator can be em- 
ployed are: 

1. To serve as a guide for setting the valves of an engine. 

2. To determine the indicated power developed by an 
engine. 

3. To determine, in connection with feed-water test, 
showing the actual amount of steam consumed, the economy 
with which an engine works. 

Among the various indicators now on the market, the Ta- 
bor Indicator is recognized as the standard, and has been se- 
lected to ■"iius-rate this article. 

All inaicators b?7e one essential plan ot construction: 
There is a steam-cy Under ana a pape7' dru7?i. 

The steam-cylinder is designed to connect with the inte- 
rior of the engine-cylinder and receive steam whenever the 
engine receives" it. - piston, which is inclosed, communi- 
cates motion to a pencil arranged to move in a straight line; 
the amount of movement being limited by the tensior of a 
spiral spring against which the piston acts. 



31 

The i)aper dntm is a cylindrical shell moimted on its axis, 
and is made to turn forward and backward by a motion de- 
rived from the cross-head of the engine. A sheet of paper, 
ox' card, as it is named, is stretched upon the drum, and a 
pencil is brought to bear upon it. In this manner, the 
instrument traces upon the paper a line termed the indicator 
diagram, which is the object sought. 

Since the motion of the card is made to coincide with 
that of the piston of the engine, and the height to which the 
pencil rises varies according to variations in the force of the 
steam, the indicator diagram presents a record of the 
pressure of the steam in the engine cylinder at every point of 
the stroke. 

Sectional View of Standard Instrumcht 




THE METHOD OF INDICATING A STEAM-ENGINE. 

There are two things to be done in making arrangements for 
indicating a steam-engine. First, the indicator must be at- 
tached to the cylinder; and second, means must be provided for 
giving motion to the paper drum. To attach the indicator, a 
hole is drilled at each end of the cylinder, and tapped for the 
reception of a half-inch steam-pipe(f()r the Tabor indicator) to 
which to connect the indicator cock. In horizontal engines^ 



3^ 

the barrel of the cylinder should be selected in prc^erenc e to 
the heads, as m the position thus secured the indicator can be 
themost easily operated. V/hercver attached, it isimportant 
that the pipe should communicate freely with the steam in 
the cylinder. The hole should not be located, for example, 
in such a position that it is covered by the piston rings at 
the end of the stroke. The pipes should be short and free 
from unnecessary bends. 

If a valve is used beneath the cock, it should be of the 
straght-way type. It is not best to connect the two ends and 
use a single indicator applied at the center. Errors are pro- 
duced by the long connections and increased number of bends 
that this requires, especially at high speeds. 

If but one indicator is available, it may be used alternately, 
first on one end and then on the other; should it be necessary 
to place the indicator at the center, as convenience in operat- 
ing generally requires in locomotive work, the errors due to 
long connections may be reduced by the employment of large 
pipes and easy bends. For these positions, a three-way cock, 
to which the indicator cock is attached, is a useful appliance. 

In drilling and tapping new holes in a cylinder, care should 
be taken that the chips do not enter it, unless they can after- 
ward be removed. If no better means can be employed, 
steam may be admitted while the work is going on, and the 
chips blown out as fast as formed. 

Before attaching the indicator, the cock should be opened 
to the atmosphere, and the pipes cleared of any loose material 
that may have lodged in them. 

INDICATOR DRIVING RIGGING. 

The motion to be given the paper drum is one that coin- 
cides, on a reduced scale, with the motion of the piston of the 
engine. It may be obtained in a variety of ways. 

The active instrument here shown, is the reducing lever, 
A C, which is a strip of pine board 3 or 4 inches wide, and 
about I % times as long as the stroke of the engine. 

It is hung by a screw or small bolt to a wooden frame at- 
tached overhead. At the lower end a connecting rod, C 
D, about one-third as long as the stroke, is at one end at- 
tached to the lever, and at the other end to a stud screwed 
into the cross-head, or to an iron clamped to the cross-head 
by one of the nuts that adjusts the gibs, or to any part of 
the cross-head that may be conveniently used. The lever A 
C should stand in a vertical position when the piston is in 
the middle of the stroke. The connecting rod, C D, when 



33 

at that point, should be about as far below a horizontal posi« 
tion as it is above it at either end of the stroke. The cords 
which drive the paper drums may be attached to a screw in- 
serted in the lever near the point of suspension; but a better 
plan is to provide a segment, A B, the center of which coin- 
cides with the point of suspension, and allow the cords to 
pass around the circular edge. The distance from edge to 
center should bear the same proportion to the length of the 




reducing lever as the desired length of diagram bears to the 
length of the stroke. On an engine having a length of 48 
inches the lever should be 72 inches, and the connecting rod 
16 inches in length, in which case, to obtain a diagram 4 
inches long, the radius of the segment should be 6 inches. 
It is immaterial what the actual length of the diagram is, but 
4 inches is a length that is usually satisfactory. It maybe 
reduced to advantage to 3 inches at very high speeds. 



34 

The coj'ds should leave segment in a line pai^allel with 
the axis of the cylinder. The pulleys over which they pass 
should mcline from a vertical plane and point to the indj 
cators wherever they may be placed. 

If the indicators and reducing lever can be placed so as to 
be in line with each other, the pulleys may be dispensed 
with, and the cords carried directly from the segment to the 
instrument, a longer arc being provided for this purpose. 
The carrier pulley on each indicator should be adjusted so as 
to point in the direction in which the cord is received. 

THE ESSENTIAL FEATURES OF THE INDICATOR DIAGRAM. 

The shape of the figure traced upon the indicator card 
depends altogether upon the manner in which the steam 




pressure acts in the cylinder. If the steam be admitted a^ the 
beginning, and exhausted at the end, of the stroke, and ad- 
mission continue from one end to the other, the shape of the 
diagram is nearly rectapgular. If the admission continue 
through only a part of tlie stroke, the diagram assumes a shape 
similar to that of Fig. No. I. These two representative 
forms have, in matters of detail, numlierless modifications. 

Fig. No. I has been taken to illustrate the essential features 
of the indicator diagram, because it exhibits clearly all the 
operations affected by pressure that commonly take place in 
the steam engine jylinder. 

This diagram shows that the a^^.Isslon of steam commences 
at A and ends at D; the cut-off commences at C and becomes 
complete at D; expansion recurs from D to E; the release or 



exhaust begins at ii and continues to the point 11 ; iiiG com- 
pression of the exhaust steam commences at G and ends at the 
admission point, A. 

The Hne A B is called the adinission line ; B C, the steam 
line; D E, the expansion li7ie; F G, the exhaust or back 
p7'essure line (or, in the case of condensing engines, the 
vacuum line); H A, the compression line; and J I, the 
atmospheric line. The curve which joins two adjacent lines, 
represents the action of the steam when one operation 
changes to another and cannot properly be classed with either 
line. 

The point of cut-off, D, lies at the end of admission; the 
point of release, E, at the beginning of the exhaust, the point 
of compression, H, at the end of the exhaust. The propor- 
tion of the whole length of the diagram borne by the distance 
of the point D from the admission end, represents the pro- 
portion of the stroke completed at the point of cut-off; so 
also in the case of the point of release, and in that of com- 
pression for the uncompleted portion of the stroke. The 
pressures at the points of cut-off, release and compression are 
the heights of these various points ahove the atmospheric line 
measured on the scale of the spring. 

THE USES TO WHICH THE STEAM-ENGINE INDICATOR Ma. 
BE APPLIED. 

There are three main objects for the deterrrination of 
which the indicator diagram may be employed: 

First. To serve as a guide in setting the valves of an 
engine. 

Second. To determine the indicated power developea by 
an engine. 

Third, To determine, in connection with a feed-water 
test showing the actual amount of steam consumed, the econ- 
omy with which an engine works. 

First. Figure No. i, shows the general features of a 
well-formed indicator diagram, the attainment of which 
should be the aim in setting the valves of an engine. The 
admission of steam is prompt, making the admission line per- 
pendicular to the atmospheric ?ine; the initial pressure is 
fully maintained up to the po^'ii'; where the steam begins to be 
cut off; the somewhat early release secures a free exhaust 
and a uniformly low back pressure, and the exhaust valve 
closes before the return stroke is comi)leted, providing for 
compression. These are the first requirements to be met in 
producing an 'Economical engine. 



3^ 

Derangement ot tne valve-gearing is revealed in the dir 
gram by tardy admission or release, by low initial pressure or 
high back pressure, or by absence of compression, either one 
of which causes an increased consumption of steam for per- 
forming the same amount of work. 

The angular position of the eccentric controls all the 
movements of the valves, but improper lengths of the con- 
necting rods which operate them, or improper proportions ot 
lap and lead, are liable to produce some of the faults we 
mention, as will also a wrong position of the eccentric. 

In regulating the exhaust of an engine, the desirability of 
employing compression should not be overlooked. In the 
first place, it serves to overcome the momentum of the recip- 
rocating parts and to reduce the strain up^u the connections 
caused by the sudden application of the pressure at admis- 
sion. In the second place, compression is desirable on the 
ground of economy in the consumption of steam. It fills the 
wasteful clearance spaces of the cylinder widi exhaust steam, 
otherwise requiring the expenditure of live steam from the 
boiler. Compression produces a loss by the increased back 
pressure which it occasions, but the loss is more than cov- 
ered by the gain resulting from the reduction of clearance 
waste. Hypothetically, the greater the amount of exhaust 
that is utilized by compression the less the consumption of 
steam. Practically, it is not advisable to compress above the 
boiler pressure. In a non-condensing automatic cut-off engine 
with 3 per cent, clearance working at 75 lbs. boiler pressure, 
cut off at one-fifth of the stroke, and exhausting under a min- 
imum back pressure, the gain produced by compressing up to 
boiler pressure over working under the same conditions with- 
out compression, should be not less than 6 per cent. Tn a 
condensing engine, working under similar condition^, the 
gain should be larger. It should be larger, also, with an 
earlier cut-off. 

The valves being in proper adjustment, the indicator dia- 
gram shows whether the pipe and passages for the admission 
and exhaust of the steam are of sufficient size. In automatic 
cut-off engines the admission line should be parallel with the 
atmospheric line, and the initial pressure should not be more 
than 3 lbs. less than the boiler pressure. The back 
pressure should not in any engine exceed i lb. when the ex- 
haust proceeds directly to the atmosphere. Much can often 
be learned by applying the indicator to the steam and exhaust 
pipes, using the same mechanism for driving the paper drum 
as that used when the indicator is operated at the cylinder. 



3/ 

Before making adjustments upon engines that have been 
long in tise, the operator should ascertain whether a valve 
which should travel in a different place has woi'n to a shoul- 
der upon its seat. If changed under such circu??istances^ 
loss from leakage may follow, sufficient in amount to neutral' 
izc the saving that might otherwise result. This is a matter 
of much importance. 

Second. The indicator is useful in determining the amount 
of power developed by an engine. The diagram reveals the 
force of the steam at every point of the stroke. The power 
is computed from the average amount of this force, which is 
independent either of the adjustment of the valves, the 
form of the diagram or of any condition upon which economy 
depends. The diagram gives what is termed the indicatec 
power of an engine, which is the power exerted by the steam. 
The indicated power consists of the net power deHvered and, 
in addition, that consumed in propelling the engine itself. 

In this connection the indicator proves invaluable for 
measuring the amount of power transmitted to a machine or 
set of machines, which the engine is employed to drive. 
The process of measuring power thus used consists in 
indicating the engine, first with the machinery in operation, 
and then with the driving belt or shaft thrown off. The 
difference in the amount oi power developed in the two 
cases is the desired result. Tenants, and those who Jet 
power, frequently employ the indicator for this purpose. 

Third A third use for the indicator is in connection with 
3. feed-water test, in determining the number of pounds of 
steam consumed byxn engine per indicated horse-power pei' 
hour. 

This quantity forms a if*reasure of the performance of an 
*^.ngine, and when compared with the performance of the best 
of its class, shows the economy with which the engine works. 
The amount of steam consumed is usually found by weigh- 
ing the feed-water before it is supplied to the boiler, the 
steam being employed during the test for no other purpose 
than driving the engine. This requires the erection of a 
weighing apparatus, the most satisfactory form of which con- 
sists of two tanks and platform scales. One tank is placed 
on the scales, and these are elevated abo\'e the second tank, 
which is of comparatively large size. The water is firs' 
drawn into and weighed in the first tank. It is then empticJ 
into the second tank, which serves as a reservoir, and from 
this it is pumped into the boiler. 

A simpler plan may be resorted to, which gives approxi- 



3» 

mate results. The feed-water is brought to a high point on 
the glass water-gauge and then shut off, and a test made by 
observing the rate at which the water boils away. A fall of 
six inches may be allowed in nearly every case without again 
feeding. The heights at the beginning and the end of the 
test being carefully observed, the amount of water evapo- 
rated and supplied to the engine is computed from the cubical 
contents that it occupied in the boilers. A test made in this 
manner can be repeated a number of times, and the results 
averaged to insure greater accuracy. 

Feed-water tests, made by measuring the water fed to the 
boiler, are of no value unless leakage of water from the boiler, 
if any exist, is allowed for. Attention should always be 
given to this point and the rate of leakage determined by 
observing the fall of water in the gauge, when no steam is 
being drawn from the boiler, a constant pressure being main- 
tained. 

A portion of the feed- water consumption of an engine may 
be found without the aid of a feed- water test, by computation 
from the diagram. Were it not for the losses produced by 
leakage and cylinder condensation, to which engines are sub- 
ject the whole amount of feed- water consumed mieht be de- 
termined in this manner. Leakage of steam often occurs 
and cylinder condensatioii is mevitable, while the extent 
to which these losses act is not revealed by any marked effect 
produced upon the lines of the diagram. The measurement 
of the consumption of steam by diagram, therefore, cannot 
be taken to show actual performance without allowing a 
margin for these losses. Much value, however, often at- 
taches to these computations. 

Besides showing the economy of an engine compared with 
the best of its class, the indicator, by means of the feed-water 
test, reveals the extent of the losses produced by leakage and 
cylinder condensation. These losses are represented by that 
part of the feed-water consumption which remains after de- 
ducting the steam computed from the diagram, or steam ac- 
counted for by the indicator^ as it is termed. One of these 
losses, condensation, is nearly constant for different engines 
working under similar conditions, and an allowance may be 
made for its amount. The other, leakage, is variable in dif- 
ferent cases, depending upon the condition of the wearing 
surfaces of valves, piston and cylinder. The fact of the pres- 
ence of the latter may be detected by a trial under boiler 
pressure with engine at rest, the leakage being revealed Dv 
escape at the indicator cock or exhaust pipe. The amount of 



this leakage may be found by computing that part of the loss 
not covered by condensation. In other words, in the case of 
leaking engines, when the indicator and feed- water test show 
that there is more loss than is produced in good practice by 
condensation, the excess represents the probable amount of 
loss by leakage. A valuable use for the indicator is thus 
found in connection with the feed-water test. To make it 
available in practice, Tables Nos. i, 2. and 3 are appended, 
showing the percentages of loss that occui from cylinder 
condensation. The quantities in Table No. I apply to that 
type of simple engine commonly used, that is, to unjacketed 
engines having cylinders exceeding twenty inches in diameter; 
the quantities m Table No. 2 apply to compound engines of 
the best class having steam jacketed cylinders; and the quan- 
tities in Table No. 3 apply to triple expansion engines of the 
best class, also having steam jacketed cylinders, all supplied 
with dry but not superheated steam. 

TABLE NO. I. 

Percentage of loss by cylinder condensattoit taken at cut-ojf 

in sifnple engines. 









Percentage of Feed- 


Percentage of Feed- 


Percentage of 


stroke 


watcr consumption 


water consumption 


completed at 


cut- 


off. 


accounted for by the 
indicator diagram. 


due to cylinder con- 
densation. 


5 






5? 


42 


10 






66 


34 


15 






71 


29 


20 






74 


26 


30 






78 


22 


40 






82 


18 


50 






* 86 


14 



TABLE NO. 2. 

Percentage of loss by cyliitder condensation taken at ciit-of^ 
in the II. P. cylinder in compound engines. 



Percentage of stroke 
compJeted at cut-c ff. 

10 

20 

30 
40 

50 



Percentage of Feed- 
water consumption 
accounted for »>y the 
indicator diagram. 


Percentage of Feed- 
water consumption 
due to cylinder con- 
densation. 


74 
76 

78 
82 

85 
88 


26 
24 
22 

18 

15 
12 



4^5 

MANNER OF TAKING DIAGRAMS 

To take a diagram, a blank card is stretched smoothly upon 
the paper drum, the ends being held by the spring clips. 
The driving cord is attached and so adjusted that the motion 
of the drum is central. The cock is opened to admit steam 
to the indicator till the parts have become heated, which 
will be after a half-dozen revolutions. On being shut off, 
the pencil or marking point is brought into conf ict with the 
paper, the stop screws is adjusted, and a fine clear line traced 
upon the card. This is the atmospheric line. The cock is 
then opened, and c.fter two or three revolutions the pencil is 
again applied and the diagram taken. If it is desired to as- 
certain the condition of the valve adjustment, the pencil 
needs to be applied only while the engine is making one rev- 
olution. But to de«ermixie power, it should be applied a 
longer time, so as to obtain a number of diagrams superposed 
on the same card. The fluctuations in the admission of 
steam, produced by gcvernors which do not regulate closely, 
ire so common, that ih\% course should always be followed to 
obtain average results. The diagram having been traced, 
and the cock shut, the pencil should be applied lightly to the 
paper to see that the position of the atmospheric line re- 
mains the same. If a nevi' line is traced, it is evidence of 
error or derangement, and the operations should be re- 
peated on a new card. 

It is well to mark upon evei}' card the date, time of day, 
and end of the cylinder from which it was taken. In ad- 
justing the valves, the boiler pressure should be observed, 
and the changes that are made before taking a diagram noted 
on the card for reference. If a series of diagrams is being 
obtained for power, they should be numbered in order, and 
the number of revolutions per minute noted, either upon 
every card, or, if the speed is nearly constant, upon every 
other one. 

If tests are to be made for power used by machines or 
tenants, a number of diagrams should be obtained mider each 
condition and the results averaged. It is well, in these cases, 
to mark each card of a set by some letter of the alphabet, 
and on the first of the set specify the machines in operation 
at the time. 

SPECIAL INSTRUCTIONS. 

When accurate work is desired, too much care cannot be 
exercised in indicating an engine, and a further consideration 



4i 

of some of the points lo be observed will aid the engineei 
in realizing their importance. 

Short steaffi connections from the cylinder to the indicator 
are desirable in all cases, and absolutely necessary with high 
cpeed engines. Avoid all turns, if possible. 

Lubrication of the indicator pistoti. — The best cylinder 
oil only should be used for this purpose. The piston should 
be removed, and the cylinder and piston cleaned and oiled 
every half-dozen diagrams. The oil contained in the steam 
ts not sufficient in any case to iabricate this piston. Alack 
of lubrication will make a jumping action in the movement 
of the pencil, showing a series of steps, not waves, on the 
diagram. 

Spring to he used. —On slow speed engines the lightest 
pring that will accommodate the pressure is best, but in 
high speed engines a heavier spring is necessary for the same 
pressure, in order to restrict the movement of the pencil bar 
and connections, and prevent their inertia from distorting the 
diagram. A waving line is the result of too great a move- 
ment of these parts. 

The tension of the spring in paper drui7i should in all 
cases be just sufficient to keep the cora tight; but this means 
that a greater tension must be used with high than with low 
peeds, to prevent the inertia of the drum over-winding itself 
and distorting the diagram; breakage of the cord also fre- 
quently results from this cause. (^, ' 

Keeping the cord leading from engine under tension. . 
This is of no importance with slow running engines, 
but when indicatmg high speed engines it is desirable 
that this cord should always be kept taut, whether the 
paper drum is running or not. A good plan is to fasten 
one end of a rubber band to the driving cord four or five 
nches from the end and attach the other end of the band to 
he indicator just below the carrier pulley, so that it always 
keeps a tension on the driving cord; then make a loop m tli': 
2nd of this cord for hooking on the indicator, and the loost* 
2nd admits of readily connecting and disconnecting without 
lilowing the driving cord to become slack for an instant. 

Length of the diagra?ns. — With slow speeds a length of 4 
in. to 4^ in. will show well proportioned diagrams, but as 
the speeds increase the diagrams must be shortened to avoid 
the effects of the inertia of the paper drum; and at very high 
speeds an instrument with the small paper drum should be 
used. Diagrams at very high speeds should not exceed 2 in 

length, and frenaently 1% in. will give better results. 



42 

The pressure of the pencil on the paper should be just 
sufficient to make a legible mark, and no more; a greater 
pressure only creates friction, and consequent inaccuracy in 
the diagram. 

Water in the indicator will make a curious but not a use- 
ful diagram, and therefore care should be exercised that the 
indicator is thoroughly heated up before a diagram is taken. 
Also, if much water is entrained in the steam, it will be nec- 
essary to leave the cylinder cocks slightly open while taking 
diagrams, as otherwise a distorted diagram is almost a cer- 
tainty. 

When taking diagrams from steam-engines, the height of 
the barometer or pressure of the atmosphere should always 
be carefully noted. This is necessary when the economy of 
the engines are to be considered, and it is desirable in all 
cases to know how much the exhaust pressure is above zero. 
Even at the sea level the pressure is constantly changing, 
and there are many engines working at places far above the 
sea level where the atmospheric pressure is always less, and 
in some cases very much less, than 14.7 lbs. per square inch, 
or 29.9 in. of murcury. Care should therefore be exercised 
in this respect, as there is a tendency among engineers to 
ignore this fact. 

All gauges in ordinary use indicate pressures above the 
atmos]:)here; if pressure gauges, or if vacuum gauges the 
amount below atmospheric pressure; but neither kind show 
the pressure above zero, or total pressure, and to arrive at 
this, the pressure of the atmosphere must be added to the gauge 
pressure in the first case, or the amount of vacuum sub- 
tracted from the atmospheric pressure in the second. 

THE METHOD OF COMPUTING THE HORSE-POWER OF AN 
ENGINE FROM THE INDICTOR DIAGRAM. 

The work done by the steam in the cylinder of an engine 
is measured by the product of thf. force exerted on the 
pistoUj mto the distance through T/bich the piston moves, 
and is usually expressed by the te. ii foot-pounds. If, for 
example, a force of 33 lbs. per squarv- inch on a piston having 
an area of 100 square inches is employed to drive the piston 
100 times over a stroke of 4 feet, the work done by the steam 
amounts to 1,320,000 ft. lbs. 7''he umount of horse-power 
which the steam develops is the fcot-pcands of work done in 
a 77iinute divided by 33.000. In the ^>xample given, the 
horse-power developed when 100 strokes are made per 
minute is 1.320,000 divided by 33,000 or 40 H. P 



4j 

The force exerted upon the piston is given by theindicavC** 
diagram, but as it varies in amount at different points of the 
stroke, it is necessary to determine the equivalent force 
which, acting constantly, vi^ould produce the same result. 
This is done by compating from the diagram what is termed 
the mean effective pressure. The product of the meaji 
effective pressure, expressed in pounds per square inch; the 
area of the cyHnder, expressed in square inches; the length of 
the stroke, expressed in feet; and the number of strokes per 
minute, which is twice the number of revolutions per minute, 
gives the number of foot-pounds of work performed per 




Fi^.^^ %, 



minute. This result, divided by 33,000 gives the amount o* 
horse-power developed. 

To compute from the diagram the mean effective pressure, 
two lines are drawn perpendicular to the atmospheric line, 
one at each end of the diagram, and the intermediate 
space divided into 10 equal parts, with a perpen- 
dicular at each point of division. A ready method 
of performing the division is to lay upon the diagram 
a scale of 10 equal parts, the total length of which 
is a small amount in excess of the length of the 
diagram. It is so placed in a diagonal position that the 
extreme points on the scale lie upon the two outside perpen- 
diculars. The desired points may then be dotted with a 
sharp pencil opposite the intermediate divisions on the 
«5cale. The points where the lines of division cross the 



• 44 

diagram should be dotted; and in locating these points they 
should be so placed that the area of the figure inclosed by 
straight lines joining them is exactly equal to the area m- 
closed by the curved line of the diagram. The proper loca- 
tions can be readily determined by the eye. 

Figure No. 2 shows the extreme perpendiculars A B and 
CD, the intermediate lines of division, the points of inter- 
section, and those points which require special location, as, 
for example, the one at E, which is so placed that the area 
inclosed by the straight lines, E F and E G, is equal to that 
inclosed by the diagram from F to G. 

The determination of the mean effective pressure consists 
now of finding the average length of the various perpendicu- 
lar lines included between the points of intersection, meas- 
ured on the scale of the spring. This may be done by meas- 
uring each line with the scale and averaging the results. A 
better and quicker method is to employ a strip of paper, one 
of the cards upon which the diagram is traced, if desired, and 
mark one after another the various distances on its edge, 
making thereby a mechanical addition, and requiring only a 
final measurement. The proper course to pursue is to lay the 
edge of the paper on the first line and mark off the distance, 
A H , starting from the end of the paper. Transfer the edge of 
the paper to the last line, and add to the first measurement the 
distance, I D. Mark off from the end of the paper one-half 
of the sum of these two distances, and from the middle point 
continue the addition for the intermediate nine divisions. 
When all have been marked measure with the scale of the 
spring, from the end of the paper to the end of the last 
addition, and divide the result by ten. This gives die mean 
effective })ressure. It is essential that one -half the sum of 
the first and last distances be taken, and the sum of this 
together with the intermediate nine be divided by ten. An 
erroneous result is obtained by taking the sum of the whole 
and dividing by eleven. 

The engineer who is so fortunate as to possess the knowl- 
edge necessary to operate an Indicator will find that his posi- 
tion is not only more secure to him, but his employers will 
be very apt to show their appreciation in a pecuniary manner. 

The use of the Indicator as a detective, detecting errors, 
misadjustments, waste and lost motion in an engine makes it 
a most necessary adjunct to the engine-room. This fact is 
becoming ^ore patent every day. 



45 
STEAM-BOILERS. 

All boilers are dividea into three different parts, viz., fire- 
surface, water-space and steam-room. Each part or division 
has a distinct and separate duty to perform. The fire-surface 
includes the furnace and combustion chamber, flues and 
tubes; the water-space is that part occupied by the water; and 
the steam-room is the reservoir which holds and supplies the 
steam necessary to run the engine. 

All steam-boilers are either internally or externally fired. 
Locomotive, marine and portable boilers are internally fired 
because the fuel is burned in an iron furnace surrounded with 
a water-jacket or v/ater-leg. Cylinder-flue, double-deck, tub- 
ulous and sectional boilers are externally fired, because the 
fuel is burned in a brick furnace lined with fire-brick. 

A perfect steam-boiler should be made of the best material 
sanctioned by use, and should be simple in construction. 
It should have a constant and thorough circulation of water 
throughout the boiler, so as to maintain all parts at one tem- 
perature. 

It should be provided with a mud-drum to receive all im- 
purities deposited from the water, and the mud-drum should 
be in a place removed from the action of the fire. 

It should have a combustion chamber so arranged that the 
combustion of the gases commenced in the furnace may be 
completed before the escape to the chimney. 

All parts should be readily accessible for cleaning and 
repairs. 

The boiler should have ample water surface for the dis- 
engagement of the steam from the water in order to prevent 
foaming. It should have a large excess of strength over 
any legitimate strain. It should be proportioned for the 
work to be done. 

It should have the very best gauges, safety-valves, fusible 
plugs, and other fixtures. 

A zvater-tiibe ^^//^r should have from lo to 12 square feet of 
heating surface for one horse-power; a tubular boiler 14 to 
18 square feet of heating surface for one horse-power; a 
fliie-boiler% to 12 square feet of heating surface for one horse- 
power ; a plain cylinder boiler should have from 6 to 10 
square feet of heating surface for one horse-power; ^locomotive 
boiler should have from 12 to 16 square feet of heating surface 
for one horse-power; a vertical boiler should have from 15 to 
20 square feet of heating surface for one horse-j^ower. 

The following table gives an approximate list of square reet 
■Oi heating surface per H. P. in different styles of boilers; the 



40 

rate of combustion of coal per hour, per square foot of grate 
surface, required for that rating; the relative , economy, and 
the rapidity of steaming: 



Type of Boiler. 


Sq. ft. for 
one H. P. 


Coal for 
eachsq. ft. 


Relative 
Kconomy. 


Relative 
rapidity of 
Steaming. 


Water tube 


lO to 12 

14 to 18 
8to 12 
6 to 10 

12 to 16 

15 to 20 


•3 

.25 
.4 

.5 

.275 

.25 


1. 00 
.91 
'19 
.69 

.80 


1. 00 

.25 
.20 


Tubular 


Flue 


Plain cyHnder 

Locomotive 


Vertical tubular. , . . . . 



HOPvSE-POWER. 

Strictly speaking there is no such thing as " horse-power 
to a steam boiler; it is a measure applicable only to dynamic 
effect. But, as boilers are necessary to drive steam-engines, 
the same measure applied to steam-engines has come to be 
universally applied to the boiler. The standard, as fixed b> 
Watt, was one cubic foot of water evaporated per hour from 
212° for each horse-power. This was, at that time, 
the requirement of the best engine in use. Since Watt'j 
time, however, this requirement has been reduced unti 
engines requiring but one-half or one-quarter a cubic foot ol 
water per hour, are in daily use. However, even thougl 
the Centennial Exposition in Philadelphia adopted as 2 
standard for tests oihoilers ^o pounds water per hour^ eva 
porated at 70 pounds pressure, from 100° for each horse 
power, the general rule, in estimating horse-power of boilers 
is based on its evaporating one cubic foot of water per horse 
power per hour. A cubic foot of water weighs 62^ pounds 

Estimating horse-poiver of boilers. — One cubic foot, 
62>^ pounds, or 6.23 gallons of water evaporated per hour 
is equivalent to one horse-power. That is, a boiler that wil 
evaporate ten cubic feet of water, or 625 pounds of water, 
62 >^ gallons of water per hour, is a boiler of 10 horse-power 

An easy approximate rule for estimating the horse-power o 
a boiler off-hand (if the boiler is a cylinder or flue boiler) i: 
to multiply the length of the boiler by the diameter, in feet 
and divide by 6; the quotient will be the nominal horse 
^(y\^^x,i% Another r///^.— Multiply the heating surface ii 
square yards hy \\iQ f re -grate surface in square feet; th 
square rooioiik^Q product will be the nominal horse-power. 



4/ 

In estimating the heating surface of a boiler, a vertical or 
ipright surface has only one-half the evaporative value of a 
lorizontal surface above the flame. That is, the sides of a 
ocomotive fire-box are only half as effective per square foot 
IS the flat top of the box. In flues and tubes, the effective 
iurface, measured on the circumference, is 1^4^ times the 
iiameter. 

To find the fire-grate surface of flue boilers. — Square the 
lominal horse-power, and divide it by the heating surface in 
quare yards ; the quotient will be the fire-grate surface m 
)quare feet — or, one square foot of fire-grate surface per 
lominal horse-power. 

To find the heating surface of a flue-boiler. — Square the 
lominal horse-power and divide that by the fire-grate surface 
n square feet; the quotient will be the heating surface in 
'quare ya7'ds. 

, Capacity of Boiler flue. — One cubic yard of boiler capa- 
city for each nominal horse-power. Steam room should be 
ibout eight times the contents of the cylinder of the engine 
mpplied with steam by the boiler. 

To find the no7mna.l horse-pozver of a locomotive boiler. — 
Square the area of the heating surface in square feet, and 
iivide by the area of the fire grate in square feet; multiply 
he quotient by .0022; the product will be the nominal horse- 
)ower. 

To find the area of the heating surface of a locomotive 
wiler. — Multiply the nominal horse-power by the area of 
he grate \n square feet; extract the cube root of the product, 
ind multiply the root by 21.2, the product is the area of the 
leating surface in square feet. 

To find the area of the fire-grate sttrfac^ of a locomotive 
W/^r. --Square the area of the heating surface in square 
eet, divide it by the number of nominal horse-power, or the 
:ubic feet of water evaporated per hour. The quotient 
tiultiplied by .0022 will be the area of the fire-grate surface in 
quai^e feet. 

Or, divide the area of the heating surface in square feet by 
5, the quotient will be the area of the fire-grate in square 
^eet, nearly. 

Tubular or mari7te boilers. — Each nominal horse-power 
equires the evaporation of one cubic foot of water per hour; 
2 square feet of heating surface, only three-fourths of the 
/hole tube-surface being taken as effective; and 30 square 
iches of fire-grate per nominal horse-power. The sectional 
rea of the tubes to be about one-sixth of the fire-grate. 



^ 



SI 

pu 
u 


3unod ui ssanjxij 
B a^lToq JO iqSpAV 


LOOOOOOOO^OOOOOO 
ir^ vo J>. r^C<r On o" ^ cf "^ »^0 cj^ C?> rf 

- - --• l-l HH M -. hH c^ 


•spunod 
I J3|ioq JO }qSpA\ 


»£>OOQO OOOi>-)QOOOOO 
cT CO Tf to i-nvcTvo tCocT o" o" •"•" CO rf t^ 


in 


•}33j UI 5qSpH 


<N rorOrOrororoco-^Ti-i-niOLO mvO 


saqoui UI ja^suiBiQ; 


0000 O O C^ "^-^VOVOOOOOOO M (N^O 
t-Hi-fCic^C^C^C^MC^C^oic^rocoro 


u 


•530J ' 

[ soBuanj JO qiSuaq 


'ro'ro'ro'V r^%t-'VTi-"VTj-'"'^^"io'LO^ 


III « 


•saqoui 
spBsq JO ss9u:>iDiqx 


cc; OD^yxrtlx «|* «!x Mloo cclx n OJc^x H!^H^^-^H^M5^N 


u 


•saqoui 
[ jpqs JO sssu^Diqx 


^^-k=..>-.;sc*hS'.!:hs:|s:s:>="»H!S 


J) 

(U 

s 

o 

ft 


•saqoui UI ;qSi3fj 


O O ^ ThO OOOOOOOvO^O^vO 
W c^) M M CS CS rocococococ^. rococo 


•saqoui 
UI jajauiBiQ 


M C<J M C^ C^ C^ COCOrOcococOCOCOcO 




•539J UT qiSusq; 


OOOOC^MC^rOMi^-^ u-iVO iJ^vO vO 


•ssqoui UI "btq; 


rocoforocococococorocococococo 


•jsquin^ 


O OOOOOvO r^ MOOOOvOvOvO o O €^ 
cocococOT^-i-oi-oi^Lot^t^t^O O CO 

VM »=4 1=1 


•qiSuaT 


l-H l-l 

00 *b "►"< 'Vo>o">o\hV)vb "vOMD "t^MD >^"K, 


•SSqOUI UI J313UIBTQ 


rOcO^^^'^LOU") i-OvO VO "O O O I>» 




-a9A\od-3SJO}-* 


-' OJ C^ CO CO 'sf 's^ LOVO x^ r-^io On O m 




•3ZIS JO -O^ 


•-< M CO "^ u-jvO t^OO C^ O '-' 04 ro -^ VO 



4^ 



y 



General rule for all classes of boilers. — Twelve square leet 
of heating surface and three-fourths square foot of fire-grate 
per nominal horse-power, are very good proportions. 

TEMPERATURE INDICATED BY THE COLOR OF THE FIRE. 
To determine the temperature of a furnace fire from the 
color of the flame: 

Faint red 960^^ F. 

Bright red. . . . > 1,300^ F. 

Cherry red 1,600^ F. 

Dull orange 2,000° F. 

Bright orange 2, 100° F. 

White heat.. 2,400° F. 

Brilliant white heat 2,700° F. 

RULES FOR SAFETY-VALVES. 

I. — To find the distance fro7n the fulcrtun at zvhich a given 
weight is to be placed on the lever ^ in order to balance a given 
pressure in the boiler. — Multiply the steam pressure oh the 
whole area of the safety-valve by the distance of the center of 
the valve from the center of the fulcrum. Multiply the dead 
weight of the lever and the valve by half the length of the 
lever, subtract this product from the first product, and divide 
the remainder by the given weight, supposed to be a cast-iron 
ball The quotient is the required distance of the weight 
from the fulcrum in inches. It is necessary, in order to find 
the steam pressure on the valve, to multiply the area of the 
valve-seat in inches by the pounds pressure per square inch. 

Suppose that the entire pressure of steam on the valve is 24 
pounds, that the center of the valve is 2 inches from the cen- 
ter of the fulcrum, and that the weight of the ball is 3 pounds 
— the first product is 24 X 2 = 48 ; the length of the lever is 
16 inches, and the united weight of the lever and valve is 
4 pounds; then the second product is (16-^2) 8 X 4 = 32. 
Then 48 — 32 = 16, and 16 -^ 3 = S/4 inches, the required 
distance of the center of the ball from the center of the 
fulcrum. 

2. 7b find the weight of the ball to hang onto a given 
length of lever, in order that the steam may blozv off at a 
given pressure. — Multiply the whole pressure on the valve 
by its distance from the fulcrum (center to center) ; from this 
product subtract the product of the weight of the lever and 
valve, multiplied by one-half of the length of the lever; 
then divide the remainder by the whole length of the lever. 
The quotient is the weight of the ball in pounds. 



For ex..mple — The pressure in the boiler is 60 p -uiuls per 
square inch on the valve, the center of the valve is 2 inches 
from the fulcrum, the weight of the valve and lever is 10 
pounds, and the length of the lever is 14 inches. 

Suppose the opening in the boiler to be 2 inches in diame- 
'cer, then 2 squared = 4 : and 4 multiplied by .7854 = 3. 1416 
square inches, the area of the valve. The whole pressure on 
the valve is 60 pounds 31416 = 188.496 pounds. The 
distance of the center of the valve from the fulcrum is 2 
inches, and 188.496 multiplied by 2 = 376.992, From this 
proauct, subtract the product of the weight of the valve and 
lever (lo pounds) by the half-length of lever, 7 inches (total 
length of lever 14 inches) or 10 7 = 70. Then 376.992 — 
70 = 306.992; and 306.922 divided by the length of the lever, 
or 14 inches, equals 21.928 pounds, the required length of ball. 

To find the pressure on the valve. — Multiply the weight of 
*1>^ ball by the length of the lever; to this product add the 
^rocruct of the v/eight of the lever and valve by the half- 
length of lever, and divide the sum by the distance of the 
valve from the fulcrum. The quotient is the pressure on the 
valve in pounds. Divide this quotient by the area of the 
valve in square inches, and the quotient will give the blow-off 
pressure. v 

Suppose the ball weighs 21.928 pounds, the length of the 
lever 14 inches, the weight of the lever and valve 10 pounds, 
the distance of the valve from the fulcrum 2 inches, then 
(21.928 X 14 = 306.992) + 10 X 7 r= 70 = 376.992; and 
376.992 7-2= 188.496 pounds, the whole pressure on the 
valve. This pressure divided by 3. 1416 square inches, the 
area of the 2" valve =60 pounds, the pressure per square 
inch on the boiler. 

SAFETY VALVE CAPACITY. 

A safety valve should be capable of discharging all the 
steam that the boiler can make with all other outlets shut. 
The United States regulations call for one-half square inch 
valve area for each square foot of grates; but where the lift 
will give an effective area of one-half that due to the diameter 
of the valve, one-fourth square inch valve area per square 
foot of grate will answer. They give the following diame- 
ters: 



51 



Area of Grate, Square Feet. 



D 

7 

o 
O 

9 

lO 
12 

14 
i6 

i8 

20 
22 
24 
26 
28 

32 

34 

a6 



Diameter of Valve, Inches. 



.... 
Common Valve. 


Improved Valve. 


ISX 


^ 


2 


I 


2'/$ 


I 


2X 


i>^ 


2^8 


i>i 


2K 


iX 


2|< 


iH 


3 


I'A 


3X 


iH 


3^8 


iH 


3>^ 


1% 


3^ 


i^ 


3^ 


2 


4 


2 


4X 


2>^ ■ 


4>^8 


2% 


4^ 


2X 


4^ 


2/8 


4I4: 


2^ 



CARE OF BOILERS. 

1. Safety Valves. — Great care should be exercised to sec 
that these valves are ample in size and in working order. 
(See rules for Safety Valves, page 82.) Overloading or neg- 
lect frequently lead to the most disastrous results. Safety- 
valves should be tried at least once a day to see if they 
will act properly. 

2. Pressure Gauge. — The steam-gauge should stand at 
zero when the pressure is off, and it should show same press- 
ure as the safety valve when the latter is blowing off. If 
not, then one is wrong, and the gauge should be tested by 
one known to be correct. 

3. Water Level. — The first duty of an engineer before 
starting is to see that the water is at the proper height. Do 
not rely on glass gauges, floats or water alarms, but try the 
gauge-cocks. 

4. Gauge-Cocks and Water-Gauges. — Both must be kept 
clean. Water-gauges should be blown out frequently, and 
the glasses and passages to gauge kept clean. 

5. Feed- Pump or Injector. — TJ-ese should be kept in per- 



52 

feet order, and of ample size. No make of pump can be 
expected t*^ be continuously reliable without regular and care- 
ful attention. It is always safe to have two ireans of feeding 
the boiler. Check-valves and self-acting feed-valves should 
be frequently examined and cleaned. . Satisfy yourself that the 
valve is acting when the feed-pump is at work. 

6. Lozv Water. — In case of low water immediately cover 
the fire with ashes (wet if possible) or any earth that may 
t>e at hand. If nothmg else is handy use fresh coal. Draw 
fires as soon as it can be dene without increasing the heat. 

Veitker tiii-n on the feed, start or stop engine^ or lift safety- 
valve until fires are out a7td the boiler cooled down. 

7. Blister and Cracks. — These are liable to occur in the 
best plate iron or steel. When first indications appears, 
there must be no delay in having it examined and carefully 
cared for. 

8. Fusible Plugs. — When used, must be examined when 
the boiler is cleaned, and carefully scraped clean on both 
water and fire sides, or they are liable not to act. 

9. Firing. — Charge evenly and regularly, a little at a 
time. Moderately thick fires are most economical, but thin 
firing must be used when draught is poor. Take care to 
keep the grates evenly covered, and allow no air-holes in the 
fire. Be especially careful to lay the coal along the sides 
and in the corners. All lumps should be broken into the 
size of a man's fist. With bituminous coal, a " coking fire-* 
(that is, hring in front, and then shoving the coal back when 
it is coked), gives the best result. Do not " clean " fires 
oftener than necessary. The cleaning of the fire is best done, 
in ordinary working, by a " rake," or other tool, working on 
the under side of the grate, and not by a " slice-bar," driven 
into the mass of fuel above the grates. 

10. Cleaning. — All heating surfaces must oe kept clean, 
outside and in, or there will be serious waste of fuel. The 
frequency of cleaning will depend on the nature of the fuel 
and water. As a rule never allow over one-sixteenth inch 
scales or soot to collect on surfaces between cleanings. Hand 
holes should be frequently removed and surfaces examined, 
particularly in case of a new boiler, until proper intervals 
between cleanings have been established by experience. 
Examine mud-drums and remove sediment therefrom. 

1 1. Hot Water Feed. — Cold water should never be fed into 
a boiler if it can be avoided, but when necessary, it should 
be caused to mix with ihe heated water before ceding in con- 
tact with any portion of the boiler. 



.S3 

12. Foaini7ig. — When fv:)aming occurs in a boiler, check- 
ing the outflow of the steam will usually stop it. If caused 
by dirty water, blowing dow^n and pumping up will generally 
cure it. In cases of violent foaming, check the draught and 
oover the fires. 

13. Air Leaks. — Be sure that all openings for admission 
of air to boiler or flue, except -through the fire, be carefully 
stopped. This is often an unsuspected cause of serious waste. 

14. BloTving Off. — If feed-water is muddy or salt, blow oft 
a portion often, according to the condition of the water. 
Empty the boiler every week or two, and fill up fresh. 
When surface blow-cocks are used, thev should be often 
opened for a few minutes at a time. Make sure no water is 
escaping from the blnw-off cock when it is supposed to be 
closed. Blow-off cocks an J check-valves should be examined 
every time the boiler is cleaned. 

15. Leaks. — Repair leaks as soon as possible after dis- 
covered. 

16. Emptying Boiler. — Never empty the boiler while the 
brick- work is hot. 

17. Rapid Llring. — Don't indulge in rapid firing. S.tean? 
should be raised slowly from a cold boiler, 

18. Standing Unused. — If a boiler is not required foi 
some time, empty and dry it thoroughly. If this is imprac- 
tical, fill it quite full of water, and put in a quantity of 
common washing soda. 

19. Genei'al Cleanliness. — -All things about the boiler- 
room should be kept clean and in good order.. Negligence 
tends to waste and decay. 

INJECTORS, 

In setting up injectors, be careful that all the supply-pipes, 
steam, water or delivery, have the same diameter (internal 
diameter) as the hole, nipple, branch, ping, tee, or reducer 
to which tljey are attache:!, and that they are as smooth, 
direct and straight as possible. 

Place a sirainer over the end of the supply pipe to keep 
out chips, dirt, etc., but be careful that the meshes or holes 
of the str?iner will equal in area the area of the sup)")ly-)-)ipe. 

In piping for steam for the injector, take steam from the 
highest ])art of the boiler so as to get dry steam. All pipes 
should l)e air and water tight, otherwise the injectr^r will 
k'ck back, take air and sjnitter. 

In ca^e the water is not to be lifted, but is fed witii a heuU 



5V 

from a tank or hydrant, place a stop cock on the pipe to 
keep the boiler from being flooded. 

A stop-valve should also be placed in the steam-pipe, be- 
tween ike steam-room and the boiler and injector, and a 
check-valve between the water- space and injector. 

PUMPS FOR SUPPLYING BOILERS. 

N^ver use smaller diameters of pipes than are called for in 
tne tables furnished by the manufacturers of the pump, as all 
makers of pumps know the capacity and work to be done by 
their pumps and their calculations are correct; however, 
when long pipes are used it is necessary to increase the diam- 
eter to allow for increased friction. Observe this suggestion 
especially in regard to suction-pipes. Use as few elbows, 
T\^# and valves as possible, and run every pipe in as direct a 
line as practicable; use full, round bends when convenient; 
use Y's instead of T's when possible. Bends, returns, T's 
5ind elbows increase friction more rapidly than length of pipe. 
Care should he taken against leaks in the sitction-ptpe, as 
a very s?nall leak destroys the effectiveness of the suction of a 
ptwip. 

See to it that a full head of water is constantly furnished 
to pump. To prevent the pump from freezing in cold 
weather, care should be taken to open the drip-plugs and 
cocks which are provided for the purpose of draining the 
pump, 

Water at a high temperature cannot be raised any consid- 
erabfe distance by suction. For pumping very hot water, 
.place the supply high enough so that the water will gravitate 
to the pump. 

A large suction-chamber placed on the suction-pipe im- 
mediately by the pump is very advantageous, and for pumps 
ranning at high speed it is a 7iecessity. Keep the stuffing- 
boxes nicely packed. Ordinary speed to run a pump is not 
over ioo feet piston travel per minute. For continuous 
boiler-feeding service about half that speed is recommended. 
Take as good care of your piwip as you do of your engine. 

SOME USEFUL INFORMATION ABOUT WATER. 

Doubling the diameter of a pipe increases its capacity /(^^/r 
times. Friction of liquids increases as the square of velocity. 

To fnd the pressure in square inches of a colu7nn of water, 
— Multiply the height of the column in feet by .434, approxi- 
mately, every foot elevation is equal to % pound pressure 
per square inch ; this allows for ordinary frictioa. 



55 

FRICTION OF WATER IN PIPES. 

Friction-loss in Pounds Pressure per square inch, for each loo feet 
of length in different size clean Iron Pipes discharging given quanti- 
ties of water per minute. 



a 2 






SIZES 


OF PIPES— 


[NSIDE 


DIAMETER. 






J2 s 


K In. 


t In. 


iKIn. 


iMIn. 


2 In. 


2MIn. 


3 In. 


4 In. 


6 .n. 


8 In. 


5 

lO 


3 3 
13. 
28.7 

50 4 
78.0 


84 
3 16 
6.98 
12 3 
19.0 

27 5 

37 
48. 


31 
1.05 
2.38 
4.07 
6.40 

915 
12.4 

16. 1 

20. 2 
24.9 
56.1 


12 

0.47 
0.97 
1.66 
2.62 

3-75 
505 
6.52 

8.15 
10. 
22.4 
39-0 










' 


0.12 












15 










t 


20 


0.42 
0-91 










' * ' 


25 
30 

35 
40 

45 

50 

75 

100 


0.21 


O.IO 








1.60 


























2.44 
5-32 
9.46 

14.9 
21.2 
28.1 
37-5 


0.81 

1.80 

3.20 

4.89 

7.0 

9.46 

12.47 

19.66 

28 06 


0-35 
0.74 

I-3I 

3-85 
5.02 

7.76 
II. 2 

15-2 

29s 
25.0 
30.8 


0.09 
0-33 










0.05 










125 

150 
175 
200 


















0.69 


O.IO 






















1.22 
1.89 
2.66 
3-65 
4-73 
6.01 

7-43 


0.17 
0.26 

0.37 
0.50 
0.65 
0.81 
0.96 
2.21 
3.88 




250 
300 
350 
400 
450 
500 
750 










c 






















.... 


12 














16 




























0.25 

0.53 
0.94 
1.46 
2.09 






























1250 
1500 




























* 





















The mean pressure of the atmosphere is usually estimated 
at 14.7 pounds per square inch, so that with a perfect vacu- 
um, it will sustain a column of mercury 29.9 inches, or a col- 
umn of water 33.9 feet high. 

To find the diafneter of a p7imp cylinder to move a given 
quantity of water per minute (100 feet of piston travel being 
the standard of speed), divide the number of gallons by 4, 
then extract tlie square root, and the product will be the 
diameter in inches of the pump cylinder 

To find tJie quantity of water ^X^^dX^A in one minute, run- 
ning at 100 feet of piston speed per minute, square the dianv 
eter of the water-cylinder in inches and multiply by 4. Ex- 
ample' Capacity of a 5 -inch cylinder is desired. The square 
of the diameter (5 inches) is 25, vvhich, multipHed by 4, 
q^ives 100, the number of gallons per minute, nearlv 



56 

71 fi^ni {l<e JiQi'sc-powcr ncv:ebsary to elevate water to a 
given !i-^igi.t niultiply the total weight of the water in 
pounds, I y the height in feet, and divide tlie product hy 33,- 
000. (An allowance of 25 per cent, should be added lor 
water li-;CLiuu, and a further allowance of 25 per cent, for 
loss in steam-cylinder.) 

TJlc area cj the steam piston in square inches, mn.ltiplied by 
the steam pressure, gives the total amount of pressure that 
can be exerted. The area of the water piston, multiplied by 
the ]3ressure of water per square inch, gives the resistance. 
A margin must be made between the power snd resistance to 
vnze ti.e |)istons at the required speed — sayfroir_ ^.ot0 40 per 
ctnt. , according to speed and other conditions. 

To find the capacity of a cylinder in gallons. — Multiplying 
the area in inches by the length of stroke in inches, will give the 
total number of cubic inches; divide this amount by 231 
(which is the cubical contents of a United States gallon in 
inches), and th6 quotient is the capacity in gallons. 

To find the quantity of water that will be discha^^ged 
throtigh an opening or pipe in the sides or bottom of a pipe ^ 
tank, barrel or vessel. — Multiply the area of orifice or 
hole in square inches by the number corresponding to height 
of surface above orifice, as per table. The product will be 
the cubic feet discharged per minute. 



Height of 




Height of 




Height of 




surface above 


Multi- 


surface above 


Multi- 


surface above 


Multi- 


Orifice. 


plier. 


Orifice. 


plier. 


0>-:f..e. 


plier 


Feet. 




Feet. 




Feet. 




5 


2o2S 


18 


9-5 


40 


14.2 


2 


3.2 


20 


10. 


45 


151 


4 


4.5 


22 


10.5 


50 


16. 


6 


5-44 


24 


II. 


60 


17-4 


8 


6.4 


26 


11.5 


70 


18.8 


m 


7-1 


28 


12. 


80 


20.1 


jf2 


7.8 


30 


12.3 


90 


21,3 


14 


8.4 


32 


12.7 


100 


22.5 


KO 


9- 


35 


133 







To find the size of hole necessary to discharge a given quan- 
tity of water tinder a given head. — Divide the cubic feet of 
water discharged by the number corresponding to height, as 
per tal:>le. The quotient will be the area of orifice required 
in square inches. 



57 



O 00 0>4^ ^0 G OO'-^r W *~J <-^- Or 4::^ Ck) Ck) Ui tj 



2 cu. 

rD 



r 3 



4^ M O OC"<r C^U^^-rl 45^ 4i. OJ oo to K> to 



4^-1^ On to to to to O O^4'^"^<-n4^4^O0OJ 

Gs k-i <-n to h) »H >-< 

b ^J 4>> On b 4*- b OC OnOJ c1> to »-i b b b o 
0<-/i4^ i-t O'^I tOO^vO^-fi>t-n >->i«<lU^C>J to 

1-1 C^ 

O-iC-M-^rO O O O O O to to tOLnO-iO-n-nLn 
00<-^000 0<-rn^;-nO OO OO 

CO 

?r 

OCOi 4i^ to to 1-1 1-1 ^ 

O0oOC^O-I^O00 ON-f^ 4^ OO i-i NH 

O OCOOi-i O^J tOC-nVOO tO ^ C^ O ■^ 4^ (^ 

crq 

OjOJN)tOpi-HMHI-IHNI-l 
4i.4uU)tOtOMI-ll-ll-.WI-*HH 



00 On OnUiOt 4^ ^i- 10 tO tO 



•-1 •-" 00 O On On On^-ti C-n4i.4u^OJ to tOt-i t-i 
K>tOMKtO-Ni-.i-.i-(»-<»-ihH^ ^^. 






re — w 



^3 



0^ 



n 0) 


1— ■ 


0) 


o 

3 




U' 




n 




w 


c 


•13 


•-t 


n 


5 


^ 


p 


Tl 


v; 




t3 


g 


?? 


3 


CL 






n> 






rD n» C 



HI C/5 
3 H-ic 
o ► o 
3^'r; :t. 
H) re o 



^ f rt 



-I f^ 









I— ( 
N 
M 

> 

o 

n 
> 



O 
> 

C/5 

> 
> 

w 
o 

w 

w 
w 
o 

c 



S8 

To find the height 7iecessa7'y to discharge a given quantity 
through a given orifice. — Divide the cubic feet of water dis- 
charged by the area of orifice in square inches. The quotient 
will be the number corresponding to height, as per table. 

The above rules represent the actual quantities that will be 
delivered through a hole cut in the pij?te; if a short pipe be 
attached the quantity "v^'ill be increased, the greatest deUvery 
with a straight pipe being attained with a length equal to four 
times the diameter of the hole. If a taper pipe be attached 
the delivery will be still greater, being \y^ times the delivery 
through the plain orifice. 

STEAM FOR HEATING. 

In estimating for steam-heating, allow one square foot of 
boiler surface for each ten square feet of radiating surface. 
Small boilers should be larger proportionately than large 
boilers. 

Each horse-power of boiler will supply from 250 to 350 feet 
of I inch pipe, or 80 to 120 square feet of radiating surface. 

Under ordinary circumstances, one horse-power will heat 
about as follows : 

Brick buildings in blocks 15,000 to 20,000 cubic feet. 

Brick stores in blocks 10,000 to 15,000 '* *' 

Brick dwellings, exposed all sides io,coo to 15,000 *' '* 

Brick mills, shops, etc 7,000 to 10,000 " *' 

Wooden buildings, exposed 7,000 to 10,000 

Foundries and wooden shops. . , .6,000 to 10,000 

It is, of course, but g^od workmanship to make ell the 
ioints steam and water tight, as the slightest leak in a steam- 
heating system is apt to do considerable damage to furniture, 
curtains, carpets, etc., if the steam is intended to heat a dwell- 
ing. Red or white lead is all right as material to make up 
joints, but graphite is much better (see page 141). For gas- 
kets there is nothing better than asbestos, and this material 
is now manufactured into gasket rings cut true to size, mak- 
ing asbestos gaskets not only the best, but furnished in a 
convenient form which will be highly appreciated by the 
steam-fitter. 

The quality of rubber sheets sold by dealers for gaskets, is 
sometimes of the poorest order, and rubber in any form, vul- 
canized or otherwise, is poor stuff to put in contact with 
steam. Gaskets made of thin lead are good, and first class 
packing can be made of candle wicking and ordinary resin 
soap, but asbestos is the best. 






59 

THE WESTINGHOUSE AUTOMATIC BRAKE. 

The Westinghouse Automatic Brake consists of the follow- 
ing essential parts : 

I St. The stea7Ji engine and piuiip^ which produce the com- 
pressed air, the supply of steam being regulated by the pump- 
governor. 

2d. The 7?iain reservoir^ in which the compressed air is 
stored. 

3d. The e7tginee'/s drake-valve, which regulates the flow 
of air from the main reservoir into the brake-pipe for releas- 
ing the brakes, and from the brake-pipe to the atmosphere for 
applying the brakes. 

4th. The equalizing -valve, which is connected to a small 
reservoir, and permits the escape of air from the main brake- 
pipe, until the pressure in that pipe throughout the entire 
train is reduced to the same pressure as that in the small 
reservoir, thus preventing the release of the forward brakes 
by the engineer closing the brake-valve too quickly, before 
the pressure in the rear part of the pipe has had time to be- 
come reduced. 

5th. The main brake-pipe , which leads from the main 
reservoir to the engineer's brake-valve, and thence along the 
train, supplying the apparatus on each vehicle with air. 

6th. The auxiliary resej'z'oir, which take^ a supply of air 
from the main reservoir through the brake-pipe, and stores it 
for use on its own vehicle. 

yth. The brake-cylinder, which has its piston-rod attached 
to the brake-levers in such a manner that, when the piston is 
forced out by air pressure, the brakes are applied. 

8th. The triple valve, which connects the brake- pipe to 
the auxiliary reservoir, and connects the latter to the brake- 
cylinder, and is operated by a sudden variation of pressure in 
the brake-pipe (i) so as to admit air from the auxiliary reser- 
voir to the brake-cylinder, which applies the brakes, at the 
same time cutting off the communication from the brake-pipe 
to the auxiliary reservoir, or (2) to restore the supply from 
the brake-pipe to the auxiliary reservoir, at the same time 
letting the air in the brake-cylinder escape, which releases the 
brake. 

9th. The couplings, which are attached to flexible hose 
and connect the brake-pipe from one veliicle to another. 

The automatic action of the brake is due to the C(Mistruc- 
tion of the triple valve, the primary ]\ans of which arc a 
piston and a slide-valve. A reduction of pressure in tlic br.\ke- 
pipe causes the excess of pressure in the auxiliary r-sorv -ir 'o 



force the piston of the triple valve down, moving the slide" 
valve tiown so as to allow the air in the auxiliary reservoir to 
pass directly into the brake-cyhnder and apply the brakes. 
When ihe pressuie in the brake-pipe is again increased above 
that in the auxiliary reservoir the piston is forced up, moving 
the slide-valve to its former position, opening communication 
from the brake-pipe to the auxiliary reservoir and permitting 
the air in the brake-cylinder to escape, thus releasing the 
brakes. 

Thus it will be seen that any reduction of pressure in the 
brake-pipe applies the drakes^which is the essential feature 
of the automatic brake. If the engineer wishes to apply 
the brakes he moves the handle of the engineer's brake- 
valve to the right, which first closes a valve retaining the 
pressure in the main reservoir and then permits a portion 
of the air in the brake-pipe to escape. To release the 
brakes he turns the handle to its former position, which 
allows the air in the main reservoir to flow into the brake- 
pipe, restoring the pressure and releasing the brakes. A 
valve called the conductor'' s valve is placed in each car, 
with a cord running the length of the car, and any of the 
trainmen, by pulling this cord can open the valve, which 
allows the air to escape from the brake-pipe. In applying 
the brake in this manner the valve must be held open until 
the train comes to a stop. Should the train break in two 
the air in the brake-pipe escapes and the brakes are ap- 
plied to both sections of the train, and should a hose or 
pipe burst the brakes are also automatically applied. 

77^^ ^^^7/^^ shows the pressure in the main reservoir and 
brake-pipe when they are connected, and the pressure in the 
brake-pipe alone when the main reservoir is shut off by the 
movement of the engineer's brake-valve. 

A stop cock is placed in each end of the brake-pipe, and is 
closed before separating the couplings, thus preventing an 
application of the brakes when cars are uncoupled. 

The diagram above the engineer's brake-valve shows the 
various positions of the handle for applying the brakes with 
any desired degree of force, for releasing the brakes, and the 
position in which the handle is to be kept after the brakes 
have been released. 

Following will be .found detailed views and descriptions of 
detached portions of the apparatus; also a full series of in- 
structions for its proper use and maintenance. ,Too much 
importance cannot be attached to that portion of the instruc- 
tions stating that engineers should use care and moderation 



6i 

in applying the brakes for ordina 'y stops. By applying 
them at a lair distance Irom the station, with moderate force, 
the tram is stopped gently and without inconvenience to the 
passengers, while if they are thrown on with the utmost force 
possible, the train is jerked in a manner that is extremely 
disagreeable to the passengers. 

AIR PUMP. 

Referring to cut, it will be seen that the steam from the 
boiler enters the top cylinder between two pistons forming 
the main valve. The upper piston being of greater diameter 
than the lower, the tendency of the pressure is to raise the 
valve, unless it is held down by the pressure of a third piston 
of sti)i greater diameter, working in a cylinder directly above 
the main valve. 

The pressure on this third piston is regulated by the small 
slide-valve, working in the central chamber on the top head. 
This valve receives its motion from a rod extending into the 
hollow piston which, as shown in the drawing, has a knob at 
its lower end and a shoulder just below the top head. This 
valve chamber in the top head, by a suitable steam-port, is 
constantly in communication with the steam space between 
the two pistons of the main valve. The steam acting on the 
third piston and holding the main valve down, admits steam 
below the main piston; as the main piston approaches the 
upper head, the reversing-valve rod and its valve are raised 
until the slide-valve exhausts the steam from the space above 
the third, or reversing-piston, vi^hen the main valve is raised 
by the steam pressure on the greater area of its upper piston, 
which movement of the main valve admits steam to the upper 
end of the main cylinder. 

When the main valve i. ^noved up to admit steam to the 
upper end of the cylinder, it opens an exhaust port at the 
lower end just below the lower steam-port, which latter is 
closed by the lower piston of the main valve; and when the 
main j^iston is on its upward stroke the upper exhaust-port is 
similarly opened. 

The air valves of the pump are similar to those used in all 
pumps. The lift of a discharge valve should not exceed one- 
sixteenth of an inch, and the lift of receiving valves should 
not exceed one-eighth of an inch. Care should be taken to 
have the lift of the discharge valves exactly the same, other- 
wise the stroke of the pump will b^ quicker in one direction 
than in the other. 



02 




TRIPLE VALVE. 

The arrangement of the auxiliary reservoir, cylinder and 
triple-valve, with the latter in section, are shown in cut 




The triple valve has a piston 5, working in the chamber Bj 
and carrying with it the slide-valve 6. Air entering from 
the main pipe passes through the four-way cock 13 by ports 
a^ <:, and the drain-cup A, and chamber B, forcing the piston 
5 into its normal position as shown, thence through a small 
groove past the piston into the valve-chamber above, and into 
the auxiliary reservoir, while at the same time there is an op'' 



b4 

communication from the brake-cylinder to the atmosphere, 
through the passage d^ e^ f ana g. Air will continue to flow 
into the auxiliary reservoir until it contains the same pressure 
as the main brake-pipe. 

To apply the brakes with their full force, the pressure in 
the main brake-pipe is allowed to escape, whereupon the 
greater pressure in the auxiliary reservoir forces the piston 
<iown on the graduating-stem 8, and in so doing closes the 
feed opening past the piston. As the piston descends, it 
moves with it the slide-valve so as to permit the air to flow 
directly from the auxiliary revervoir into the brake-cylinder, 
which applies the brakes. The brakes are released by re- 
admitting pressure into the main brake-pipe from the main 
reservoir, which pressure, being greater than that in the 
auxiliary reservoir, forces the piston back to the position 
shown in the drawing, when the air in the brake-cylinder 
escapes. To apply the brakes gently, a slight reduction is 
made in the pressure in the main brake-pipe, which moves 
the piston down siowly untd it is stopped by the graduating 
stem 8 a.nd spring 9 , at this point the opening /, in the slide- 
valve is opposite the port/", and allows air from the auxiliary 
reservoir to feed through a hole in the side of the slide-valve 
and through the opening/, into the brake-cylinder ^: When 
the pressure in the auxiliary reservoir has been reduced by 
expanding into the brake-cylinder, until it is the same as the 
pressure in the main brake-pipe, the graduating spring pushes 
the piston up far enough to close a small valve 7, which is 
placed in the feed opening /, of the slide-valve. This causes 
whatever pressure is in the brake-cylinder to be retained, 
thus applying the brake with a force proportionate to 
the reduction of pressure in the brake-pipe. To prevent 
the application of the brakes, from a slight redu-^tion of 
pressure caused by leakage in the brake-pipe, a semi- 
circular groove is cut m the body of the car-cylinder, §-^ of 
an inch in width, ^4 of an inch in depth, and extending so 
that the piston must travel three inches before the groove is 
covered by the packing leather. A small quantity of air, 
such as results from a leak, passing from the triple-valve into 
the car-cylinder, has the effect of moving the piston slightly 
forward, but not sufficiently to close the groove, which per- 
mits the air to flow out past the piston. If, however, the 
brakes are applied in the usual manner, the piston will be 
moved forward, notwithstanding the slight leak, and will 
cover the groove. It is very important that the groove shall 
be three inches long, and shall not exceed in area the dimen- 
sions given above. 



©5 

\ When the handle of the four- way cock 13, is turned down, 
^ere is a direct communication^ from the main brake-pipe t0 
>he brake-cylinder, the triple-valve and auxiliary reservoii 
being cut out, and the apparatus can be worked as a non- 
automatic brake by admitting air into the main brake-pipe 
and brake-cylinder, to apply the brakes. When from any 
cause it is desirable to have the brake inoperative on any 
particular car, the four-way cock is turned to an intermediate 
position, which shuts off the brake-cylinder and reservoir, 
leaving the main brake-pipe uTiobstructed to supply air to 
the remaining vehicles. 

The drain cup A collects any moisture that may accumu- 
late, and is drained by unscrewing the bottom nut. 

engineer's brakb-valve. 




The handle i of the engineer's brake-valve terminates in S 
Jcrew with a coarse thread, which compresses a spring 4 upoi 
'he top valve 3; this top valve fits into a slot in the handle ' 



66 

and into a slot in the main valve 6, so that the handle and the 
two valves must turn simultaneously. In the position shown 
in the drawing, which is for releasing the brakes, the top valve 

3 leading to the atmosphere is kept closed by the compression 
of the spring 4, and the air passes freely fro«m the main reser- 
voir to the brake-pipe through the openings of the main valve 
and the body of the brake-valve. After the brakes are off, 
the handle is moved against the second stop, a short distance 
to the right, which turns the main valve so that the main 
passages to the break-pipe are closed. Air can, however, 
pass through the small valve 7, and thence to the brake-pipe 
through a small opening not shown in the drawing. This 
small valve 7 is held down by a spring whose resistance is 
equal to 20 lbs. per square inch, hence the pressure in the 
main reservoir will be 20 lbs. greater than that in the brake- 
pipe, which surplus pressure insures the certain release of the 
brakes when desired. To apply the brakes the handle is 
moved still further to the right, when the opening from the 
small valve 7 is also closed, cutting off all communication 
from the main reservoir to the brake-pipe, at the same time 
the action of the screw lifts the handle and relieves the spring 

4 from pressure, when the air in the brake-pipe lifts the valve 
3, and escapes, until an equilibrium is established between 
the air pressure and the pressure of the spring on the valve 3, 
thus reducing the pressure in the brake-pipe to an extent cor- 
responding to the distance which this handle is moved. 

To apply the brakes suddently the handle is turned the entire 
distance to the right, which relieves the spring ot all compres- 
sion, allowing the valve 3 to rise, and all of the air in the 
brake-pipe to escape. 

After the train is stopped, the brakes are released by turn- 
ing the handle to the position shown in the drawing. 

The pump-governor is shown in the cut, the object of 
which is to automatically cut off the supply of steam to the 
pump when the air pressure in the train-pipe exceeds a cer- 
tain limit, say 70 lbs. 

The operation of this governor is as follows: The wheel 8 
is screwed down so as to permit the valve 10 to be unseated 
by the excess of pressure on the upper side of the valve per- 
mitting steam to pass through the openings A and B to the 
pump. A connection is made from the train-pipe to the up- 
per end of the governor, and the compressed air passes 
around the stem 14 to the upper side of the diaphragm plate 
18, which is held to its position by the spring 16, which latter 
Is of sufficient strength to resist a pressure of say, 70 lbs< 



TO TRAIN PIP£ I UMP-GOVERNOR, 




68 

per square inch on diaphragm. As soon as the air pressure 
on the diaphragm i8 exceeds this amount, it forces the dia- 
phragm down, unseating the valve 13, and allowing the 
steam on the upper side of the valve 10 to escape through 
the exhaust 6, which causes an excess of steam pressure on 
the lower side of the valve 10, forcing the valve against its 
seat, and cutting off the supply of steam to the pump. 

When the pressure in the train-pipe is diminished by ap- 
plying the brakes, the diaphragm is restored to the position 
shown by the action of the spring 16. The valve 13 is 
seated by the spring 12, and the steam pressure passing 
through the portC, accumulates on the upper side of the valve 
iO, forcing it down, and opening the passage for steam to the 
pump until the air pressure is again restored to the required 
limit of 70 lbs. 

The use of the governor not only prevents the carrying of 
an excessive air pressure by the engineers^ which may result 
in the sliding of the wheels, but it also causes the accumulatiou 
of a surplus of air pressure in the main reservoir while the 
brakes are applied, which insures the release of the brakes 
without delay. It also limits the speed of the pump and con- 
sequently the wear. 

EQUALIZING VALVE. 

The proper application of the brakes depends upon the 
amount of air discharged from the train pipe, and the manner 
in which it is discharged. The amount of air to be dis- 
charged -also depends upon the length of train. 

As stated in the general description of the brake apparatus, 
the brakes are applied by reducing the pressure in the train 
pipe, and are released by increasing the pressure. On long 
trains engineers have found it very difficult to discharge the 
air in such a way that they will not first cause a large reduc- 
tion in the front portion of the pipe, and then an increase 
tending to release the brakes on the tender and two or three 
cars next; the increase of pressure being due to the expan- 
sion of the air in the pipes of the rear portion of the train. 
The equalizing valve which is shown in Plate 6 (which serves 
also as a large drain cup), is a device which automatically 
provides for the proper discharge of the air on all of the 
vehicles, 'back of the tender, the engineer having to discharge 
only the required amount from his brake-valve, and always a 
given amount for a certain degree of application, whether the 
train consists of one or fifty cars. 

In the position shown, the air from the equalizing reservoir 
passes through the ports of the equalizing valve as shown by 



09 

the arrows and into the train pipe. When the pressure m 
the equalizing reservoir is reduced slightly to apply the 
brakes, the piston 15 moves down carrying the valve 11 from 
its seat and permitting the air in the train pipe to escape 
through the ports d^ e and g, until the pressure in the train 
pipe equals that in the equalizing reservoir, when the piston 
and valve 1 1 return gradually to the position shown. When 
it is desired to apply the brakes quickly with full force a con- 
siderable reduction is made in the pressure in the equalizing 
reservoir and the piston moves down its entire distance car- 
rymg with it the slide valve 4 and uncovering the upper port 
g^ while air is also allowed to escape through the port /and 
the lower port g^ thus permitting a rapid escape of the press- 
ure in the train pipe until it equals that in the reservoir, 
when the valve returns to the position shown. 

INSTRUCTIONS. 

General, — In making up trains all couplings must be united 
so that the brakes will apply throughout the entire train. 
The cocks in the brake-pipe must all be opened (handles point- 
ing down), except that on the rear of the last car, which must 
be closed. 

In detaching engines or cars the couplings must invariably 
be parted by hand; the cocks in the main brake-pipes must 
always be closed before separating the couplings, to prevent 
application of the brakes. 

If the brakes are applied when the engine is not attached 
to the train or car, they can be released by opening the re- 
lease cock usually put in the end of the brake-cylinder. 

The adjustment of the break-gear should be such, that 
when the brakes are full on, the pistons in the brake-cylinders 
will not have traveled to exceed eight or nine inches. Ihis 
will allow for wear of shoes, stretching of rods, springing of 
brake-beams, etc. In narrow gauge freight apparatus the 
adjustment must be such that the piston will not travel more 
than five or six inches. 

Great care must be exercised when taking up the slack in 
the brake connections to have the levers and pistons pushed 
back to their proper places and the slack taken up by the 
under connection, or dead levers. 

The brake-cylinders must always be kept clean so that 
they will readily release when the air has been discharged, 
and should be oiled once in three months. The last date of 
oiling should be marked on the cylinder with chalk. 

I For the automatic break the handle of the four-way cock 
must be turned horizontally. If turned down it will be 



70 

changed to the simple air-brake; if turned midway between 
these two positions, it will close communication with the 
brake-cylinder and reservoir, and should be so turned when 
desirable to have the brakes out of use on any particular car 
on account of the breaking of rods, etc. It is very important, 
in order to avoid detentions, to keep the handles of these 
four-way cocks in their proper positions. 

In cold weather the triple valve should be drained fre- 
quently, to let out any water that may have collected. Slack 
the bottom nut of the triple valve about half a turn, let the 
water escape and screw it up again. The valve for the ap- 
plication of the brakes from the inside of the car should be 
kept tight, and must be examined by the inspectors. 

Enginee7's must see that the steam-cylinder is kept well 
lubricated; that the air-cylinder is sparingly lubricated with a 
small quantity of 28^ gravity West Virginia well oil; (tallow 
or lard oil must not be used in the air-cylinder); that the 
pump is constantly run, but never faster than is necessary 
to maintain the required air pressure; and that air from 50 
to 60 pounds pressure for low speed or way trains, and from 
70 to 80 pounds pressure for express trains is carried. 

For ordinary stops the brakes should be applied lightly by 
opening the valve or cock and closing it gently when the 
pressure has been reduced from 4 to 8 pounds on the gauge. 

The brakes are fully applied when the pressure shown on 
the gauge is reduced 20 pounds. Any further reduction is a 
waste of air. 

In releasing the brakes, the handle of the brake-valve 
must be moved quite against the stop and be kept there for 
about ten seconds, and then moved back against the inter- 
mediate stop, which is the feed position, and where it must 
remain while the train is running. 

Engineers, upon finding that the brakes have been ap- 
plied by the train men or automatically, must at once aid in 
stopping the train by turning the handle of the brake- valve 
toward the right, thus preventing escape of air from the main 
reservoir. 

The slioes of the driving-wheel brakes should be so ad- 
justed by turning the screws that the piston moves up from 
3 to 4 inches when the brakes are applied. 

It is important to drain the water out of the main reservoir 
once a week, especially in winter time, and oftener if the 
pump-rod is not kept well packed. 

If cars having different air pressures be coupled together, 
the brakes ^v;i I apply themselves on those which have the 



highest pressure. To insure the certain release of ait the 
brakes in the train, and also that trains may be charged 
quickly, the engineer must carry the maximum piessure in 
the main reservoir before connecting to a train, and then put 
the handle of his brake- valve in the release position until the 
train is charged with air. If the brakes on the engine and 
tender thus apply themselves by being coupled to a train not 
charged, they should at once be taken off by opening the re- 
lease cock from the brake-cylinders, which ought to be so 
arranged as to be worked from the foot-plate. 

Train-Men. — After making up or adding to a train, or 
after a change of engines, the rear brakeman shall ascertain 
whether the brake is connected throughout the train. 

When the hose couplings are not used for connecting the 
brakes between two vehicles, they must be attached to their 
dummy couplings. 

When there is occasion to apply the brakes from the cars, 
the valve must be held open to allow the air to escape until 
the train is brought to a stand-still, but this method of ap- 
plication should only be used in cases of emergency. 

Train-men must in all cases see that the hand-brakes are 
off before starting. 

Before detaching the engine or any carriages, the brakes 
must be fully released on the whole train. Neglecting this 
precaution, or setting the brakes by opening a valve or cock 
when the engine is detached, may cause serious incon- 
venience in switching. 

The pipes and joints must be kept tight, and when leaks 
are discovered they should be corrected, if serious, before the 
car is again used. 

HOW TO APPLY AND RELEASE THE WESTING- 
HOUSE AUTOMATIC BRAKE. 

The brakes, as has been explained, are applied when the 
pressure in the brake pipe is suddenly reduced, and released 
when the pressure is restored. 

It is of very great importance that every engineer should 
bear in mind that the air pressure may sometimes reduce 
slowly, owing to the steam pressure getting low, or from 
the stopping of the pump, or from a leakage in some of the 
pipes when one or more cars are detached for switching pur- 
poses, and that in consequence it has been found absolutely 
necessary to provide each cylinder with what is called a leak- 
age groove, which permits a slight pressure to escape with- 
out moving the piston, thus preventing the application of the 



72 

brakes when the pressure is slowly reduced, as would result 
from any of the above causes. 

This provision against the accidental application of the 
brakes must be taken into consideration, or else it will some- 
times happen that all of the brakes will not be applied when 
such is the intention, simply because the air has been dis- 
charged so slowly from the brake-pipe that it only represents 
a considerable leakage, and thus allows the air under some 
cars to be wasted. 

It is thus very essential to discharge enough air in the first 
instance, and with sufficient rapidity, to cause all of the leak- 
age grooves lO be closed, which will remain closed until the 
brakes have been released. In no case should the reduction 
in the brake-pipe for closing the leakage grooves be less than 
four or five pounds, which will move all pistons out so that 
the brake-shoes will be only slightly bearing against the 
wheels. After this first reduction the pressure can be re- 
duced to suit the circumstances. '^^ 

On a long train, if the engineer's brake-valve be opened 
suddenly, and then quickly closed, the pressure in the brake- 
pipe, as indicated by the gauge, wiU be suddenly and consid- 
erably reduced on the engine, and will then be increased by 
the air pressure coming from the rear of the train ; hence it 
is imporiant to always close the engineer's brake-valve slowly, 
and in such a manner that the pressure as indicated by the 
gauge will not be increased, or else the brakes on the engine 
and tender, and sometimes on the first one or two cars will 
come off when they should remain on. It is likewise very 
important, while the brakes are on, to keep the engineer's 
brake-valve in such a position that the brake-pipe pressure 
cannot be increased by leakage from the main reservoir, for 
any increase of pressure in the brake, pipe causes the brakes 
to come off. 

On long down grades it is important to be able to control 
the speed of the train, and at the same time to maintain a good 
working pressure. This is easily accomplished where the 
pressure-retaining valve is not in use, by running the pump 
at a good speed, so that the main reservoir will accumulate a 
high pressure while the brakes are on. When, after using 
the brakes some time, the pressure has been reduced to sixty 
pounds, the train pipes and reservoirs should be recharged as 
much as possible before the speed has increased to the maxi- 
mum allowed. A greater time for recharging is obtained by 
considerably reducing the speed of the train just before re- 
charging and by taking advantage of variation in the grades. 



73 

There should not be any safety-valves or leaks in the main 
reservoir, otherwise the necessary surplus pressure fcttr 
quickly recharging cannot be obtained. 

To release the brakes with certainty it is important to have 
a higher pressure in the main reservoir than in the main 
pipe. If an engineer feels that some of his brakes are not 
off, it is best to turn the handle of the engineer's brake- valve 
just far enough to shut off the main reservoir, and then pump 
up fifteen or twenty pounds extra, which will insure there- 
lease of all of the brakes; all of which can be done while the 
train is in motion. 

For ordinary stops great economy in the use of air is 
effected by, in the first instance, letting out from eight to 
twelve pounds pressure, while the train is at speed, taking 
care to begin a sufficient distance from the station, 

BRAKE POWER. 

To obtain the best results, it is important to have the brak- 
ing force proportioned to the weight of the car, or more par- 
ticularly speaking, to the load carried by those wneels upon. 
w^hich brakes act. After long experience it has been decided 
to recommend such a proportion of brake levers that a press* 
ure of fifty pounds per square inch on the brake piston will 
bring a force against the brake-blocks on each pair of wheels 
equal to the load carried by them; thus, owing to a great 
variation of cars, it is impossible to have uniform brake 
levers. 

For convenience it has been found best to cut the brake 
connection which joins the brakes of both trucks and to inter- 
pose at this point the brake-cyHnder, having with it two levers 
and a tie-rod. With this arrangement it is only necessary to 
get the proper portion of these cylinder levers. 

The following rules will enable those whose duty it is to 
attach brakes to proportion the levers, so as to carry out tile 
foregoing recommendation. 

RULE FOR CALCULATING CAR LEVERS. 

The air pressure is rated at fifty (50) pounds per squarr 
inch on piston, when the brakes are fully applied. (50 lbs. 
per square inch gives about 4,000 lbs. for lo-inch cylinder^ 
and 2,500 lbs. for 8-inch cylinder.) 

To find the leverage regiiired. — Divide the weight of the caj 
resting upon the brake-wheels by the zvhole pressure on 
piston. 

To find proportion of brake beam levers, — Divide the whoit 
length of lever by short end. 



74 

To find the total brake beam leverage. — Multiply propor- 
tion of lever by two (2) for the Hodge system, and by four (4) 
for the Steve7ts\ 

To find proportion of cylinder lever. — Multiply the whole 
iength of lever by either the required leverage, or the total 
brake beam leverage, and divide by the sum of both, the result 
will give the length of one end of the lever. 

If the required leverage is greater than the totalhrake beam 
leverage, the long end of the lever must go next to the cylin- 
der; if less, the short end must go next to the cylinder. 

Dead levers must be made in the same proportion as the 
other truck levers. 

Exa niple— Hodge Syste77i . 

Weight of car 36,000 lbs. 

Total pressure on lo-inch piston 4,000 " 

Total length brake beam lever 28 inches. 

Length of short end of brake beam lever 7 " 

Total length of cylinder lever 24 " 

36,000 -f- 4,000 = 9, leverage required. 

28-^ 7 = 4X2=8, total brake beam leverage. 

24 X 8 = 192 -f- (8 + 9) = 1 1.3, short end cylinder lever. 

24 — 1 1.3 = 12.7, long end cylinder lever. 

Exai7iple — Stevens'* System, 

Total length of cylinder lever 36 inches. 

36,000 — 4,000=9, leverage required. 

28-T-7 = 4>^4= ^^> total brake beam leverage. 

36 X 9 =324-7- (9+ 16) = 12.96, short end cylinder lever. 

36 — 12.96 = 23.04, long end cylinder lever. 

INFLUENCE OF ROADS AND WEATHER ON 
TRACTION. 

According to tests by E. Whyte-Smith, and communicated 
to the Institute of Electrical Engineers, the pull ■ required 
per ton of vehicle for various roads and for three different 
conditions of weather is given in the following table: 



Asphalt, 


22 


23 


22^ 




Wood, 


22 


31 


36 


Pull 


Macadam (good). 


52 


50 


49 


> in lbs. 


Macadam, . 


60 


51 


50 


per ton. 


Macadam (soft), . 


97 


51 


52 J 






/5 
COLD CHISELS. 

□^^« I Figures i and 2 are drawings of flat 
\\ \ I chisels. The difference between the two is 
11/ ^^^U as the cutting edge should be parallel 
c==* V with the flats on the chisel, and as Fig. i 
**** ^"^ has the widest flat, it is easier to tell with it 
when the cutting edge and the flats are parallel; therefore the 
broad flat is the best guide in holding the chisel level to the 
surface to be chipped. Either of these chisels is of a proper 
width for wrought iron or steel, because chisels used on 
these metals take all the power to drive that can be given 
with a hammer of the usual proportions for heavy clipping, 
which is: Weight of hammer, i^ lbs.; length of hammer- 
handle, 13 in. ; the handle to be held at its end, and swinging 
back about vertically over the shoulder. 

If so narrov/ a chisel be used on cast iron or 
brass with full force hammer blows, it will 
break out the metal mstead of cutting it, and 
the break may come below the depth wanted to 
chip, and leave ugly cavities. 

So for these metals the chisel must be broader, 
as in Fig. 3, so that the force of the blow will be spread over 
a greater length of chisel edge, and the edge will not move 
forward so much at each blow, therefore it will not break the 
metal out. 

Another advantage is that the 
Droader the chisel the easier it is to 

dY y^ f / hold its edge fair with the work 
U,^^^ — %^^/^ surface, and make smooth chipping. 
The chisel-point must be made as 
-^^ ' thin as possible, the thickness shown 

in sketches being suitable for new 
chisels. In grinding the two faces to form the chisel, be care- 
ful to avoid grinding them rounds as shown in a in the mag- 
nified chisel ends in Fig. 4; the proper way is to grind them 
flat, as in b in the same sketch. Make the angle or edge of 
these two faces as sharp or acute as you can because the 
chisel will then cut easier. 

For cutting brass, hold the chisel about 
the angle shown in c. Fig. 5; for steel, 
that at d same figure. The difference is, 
that with hard metal the more acute 
angle dulls too quickly. 

For heavy chipping, the point may be 
made flat as in Fig. i., or curved as in 





70 




jt«^ 



1 ^1 jy.« 



Fig* 3' 9 which is the best, because the corners are relieved 
from duty, and are therefore less liable 
to break. The advantage of the curve 
is greatest in fine chipping, because, as 
seen in Fig. 6, a hner chip can be 
taken without cutting with the corner, 
and these corners are exposed to the 
eye in keeping the chisel edge level with 
the work surface. 

In any case do not grind the chisel 
hollow in its length, as in Fig. 7, or as shown 
exaggerated in Fig. 9, because, in that case 
the corners will dig in and cause the chisel 
to be beyond control; besides that, there will be 
a force, that, acting on the wedge principle, will 
operate to spread the corners and break them off. 

Do not grind the faces wider on one side than on the other 
of the chisel, as in Fig. 8, because, in that case, the flat of the 
chisel will form no guide to let you know when the cutting 
edge is level with the work surface. Nor must 
/■^-wv y°^ grind it out of square with the chisel body, as 
/ /y^ ill ^ ig- io> because, in that case, the chisel will 
(^^__^ ^ be apt to jump sideways at each hammer-blow. 
»'**% A quantity of metal can be removed quicker by 

using the cape chisel in Fig. 11, to first cut out 
grooves, spacing these grooves a little narrower 
apart ^ than the width of the flat chisel, and thus 
relieving its corners. The chisel end must be shaped 
as at a and b^ and not as at c in Fig. 
II, so as to be able to move it side- 
ways, to guide it in a straight line, 
and the parallel part at c will inter- 
fere with this, so that if the chisel is 
started a very little out of line, it will go still 
further out of line, and cannot be moved 
sideways to correct the fault, 
round-nosed chisel. Fig. 12, must not be made 
straight on its convex edge; it may be straight 
from -^ to ^ but from ^ to the point, it must 
be beveled, so that by altering the height of 
the chisel head it is possible to alter the depth 
of the cut. 

The diamond point chisel in Fig. 14 and 15, 
must be shaped to suit the work, because if it is not to be 
used to cut out the corners of very deep holes, you can bevel 




The 




n 



It at m^ and these bring its point ^, central to the body of 
the steel, as shown by the dotted line ^, rendering the 
corner x less hable to break, which is the great trouble with 






this chisel; but in cutting deep holes the bevel at m must 
be omitted, and you must make the edge straight, as at r in 
Fig. 15.^ 

The side chisel obeys the same rule, so you may make it 
^^ bevel at w, as in Fig. 16, for shallow holes, ana? 
/h^l lean it well over in using, and make the side v w 
Y\ N straight along its whole length for deep holes ; but 
in all chisels for slots or mortises it is desirable to 
have if circumstances will permit, some bevel on the 
side that meets the work, so that the depth of the 
cut can be regulated by moving the chisel head. 

In all these chisels, the chip on the work steadies 
the cutting end, and it is clear, th?t the nearer 
you hold the chisel at its head the steadier yoi can hold it, 
and the less the Hability to hit your fingers, while the chipped 
surface will be smoother. 

To take a chip off wrought iron, if it is a heavy chip, 
tand well away from the vice, as an old hand would do, in- 
stead of close to it; if, instead, you wish to take a light chip, 
you must stand nearer to the work, so that you can watch 
the chisel's action and keep its depth of cut level. In both 
cases you must push the chisel forward to its cut, and hold it 
as steadily as possible. 

It is a mistake to move it at each blow, as many do, be- 
cause it cannot be so accurately maintained at the proper 
leight. Light and quick blows are always necessary for the 
finishing cuts, whatever the kind of metal may be. 

TURNING OR LATHE TOOLS FOR METALS. 

Few lathe tools, except scrapers, can be used indiscrimi- 
[lately for cast iron, wrought iron or brass; each metal needs 
its particular set of tools, differing not so much in the shape 
i^f their cutting edges, as in the angles which they make with 
:he surface of the work to be turned. Thus, Figs. 17, iSv 



7» 

in are each intended to represent in profile the ordinary 
roushing-dow.1 tool, but their angles are very dififerent the 
Som the other. Fig. 17. beingcnly suitab e for 'trough 
iron. Fig. 18 for cast iron and Fig. 19 for brass. In all 

1- 




\if» 






these everything (temper of course excepted) depend upon 
tKgle a^t whkh the tools are ground. The brass tool with 
the flat face would not cut the iron, but would simply scratch 
if while the iron tools would hitch in the brass and tend to 
« chatter " or " draw-in. " Neither would the tool ground at 
an acute'angle for wrought iron, cut cast metal, but would 
itself become broken off at the tip, while the thicker casc iron 
tool would not take clean shavings off wrought iron, -b ig, 20 
is a common roughing tool for cast 

iron. The side view gives a proper __„_ \- 

angle to insure a clean cut without f- ^^ j ^». 
breaking the top across in the di- -^J -^^ ' 

rection of the dotted line. The ^ " 

angle is drawn on the supposition , ., , .-, . t,„. 

that the toolis held horizontally, as indeed it should be but 

a tool that will not cut nicely ^^. ^^^^^^^^^^^^^^l^f^^^^^^^^ 
often work by inclining it at a slight angle, /either is the 
angle at which a tool should be grouna, m order to cut well 
horizontally, necessarily the same. It should be about 65^^ 
with the verical for cast iron, but may vary slightly either 

"^Yn fact, not one workman in ten could say what angle he 
trrinds his tools to ; he simply judges the proper angle by his 
4e The angle which the front of the tool makes with the 
work may vary somewhat more than the upper face, depend- 
Lg up^n the diameter of the work to be turned but should 
aot slope more than 4^ or 5° from the vertical for cast iron 
{Fig. 18). If it becomes excessive the tool is weak and soon 
breaks off. 

: These details may seem trivid, but they are really of the 
utmost importance. These sketches are taken from tools ui 



79 

actual use and doing their work well. Fig 21 shows a round 
nose, Fig. 22 a parting tool, Fig. 23 a knife-tool for finishing 
edges and faces of flanges, and ends and sides of work, eithei 
right or left-handed (Fig. 24). The end views of these tools 
show the upper and clearance angles, which, are about the 
same as in Fig. 18, but may vary somewhat according to the 
work required. 

Figs. 25 are boring-tools for hollow cylinders, tools capa- 



ble of much modification, their cutting edges not only taking 
the forms of all other tools, but each form also being often 
right and left-handed. In reference to the more usual shape, 
that of the round nose for boring, when used simply as a 
roughing tool, the shape ^ showing it 
/ • -) in place, with -the axis of the cutting 

C ^ ] I !/ angle in the direction of the dotted 



G S J X line, is better than that of «, because 
U in b the true cutting edge is carried 

*■" forward. Hence, in work-shops the 

cutting tools generally take the form b^ and the scrapers form a. 
Fig. 26 is a square nose for taking finishing cuts, and Fig. 



I 




JV^Jlt JWi, ^^'^^ 

27 is a tool for scraping; Fig. 28 is a spring tool, also used 
for finishing a turned surface; Figs. 29 and 30 are for finish- 
ing hollows and rounded parts of work, and are either kept 
in different sweeps or ground to circles as wanted. These 

latter forms are only used for smoothing and polishn.g^ and, 
as they act simply as scrapef s, are flat on their upper surfaces. 

For grinding tools, a very handy little grind- 
stone may be made in this fashion (Fig, 31). A 
piece of broken grindstone, 2 inches thick, is * . . 
rudely clipped round to 7 inches in diameter, and * [ ^ 
a ^ ixich hole bored through the center with a 
common stone-bit; two wooden washers, a\ ^ ^' 
inch thick by 4 inches in diameter, also have Yz 



50 



incn iiolesj bored in their centers. A % inch bolt, b, thrust 
through the whole keeps them firmly together with the stone 
in the center. 

As the stone is intended to work chucked between cen- 
ters, a small drilled hole is run both into the bolt head and 
into the screwed end, and a V shaped slit, <r, is filed in the 
head to hold the fork. 

Turned up in place, it makes an efficient little grindstone, 
in readiness for use the moment it is slipped into the lathe. 
A shallow tin pan slipped between the stone and bed will 
catch any mess that may be made. 

The grindstone or emery wheel alone is used to sharpen 
roughing-down tools; but those used for smoothing and pol- 
ishing should have the edge finished with an oil-stone. 

NOTES ON BELTING. 

Having your machinery, shafting and pulleys properly 
arranged, preparatory to belting, the next thing to be deter- 
mined is the length and width of the belts. When it is not 
convenient to measure with the tape-line the length required, 
the following rule will be found of service: 

Add the diameter of the two pulleys together; divide the 
result by 2, and multiply the quotient by s%', then add this 
product to twice the distance between the centers of the shafts^ 
and you have the length required. The width of the belt 
depends on three conditions:—!, The tension of the bell; 2, 
the size of the smaller pulley and the proportion of the sur- 
face touched by the belt; 3, the speed of the belt. _ 

The working adhesion of a belt to the pulley will be m 
proportion both to the number of square inches of belt con- 
tact with the surface of the pulley, and also to the arc of the 
circumference of the pulley touched by the belt. This ad- 
hesion forms the basis of all right calculations in ascertaining 
the width of belt necessary to transmit a given horse-power. 

In locating shafts to be connected by belts, care should be 
taken to secure a proper distance one from the other. This 
distance should be such as to allow a gentle sag to the belt 
when in motion. A general rule may be stated as thus: 
When narrow belts are to be run over small pulleys, 15 feet 
is a good average, the belt showing a sag of iK to 2 inches. 

For larger belts, working on larger pulleys, a distance ot 
20 to 25 feet does well, with a sag of 2)^ to 4 inches. 

For main belts, working on very large pulleys, the dis- 
tances should be from 25 to 30 feet, the belts workmg well, 
with a sag of 4 to 5 inches. 



8i 

If the distance be too great the weight of the belt wiH 
produce a very heavy sag, which is a decided objection, pro- 
ducing great friction on the bearings, while at the same time 
the belt will have an unsteady flopping motion which will 
destroy both the belt and machinery. Connected shafts 
should never be placed one directly over the other, as in that 
case the belt must be kept very tight to do the work. 

It is best that the angle of the belt with the floor should 
not exceed 45 degrees. It is also best in locating the ma- 
chinery and shafting so that the belts will run ofl"on opposite 
sides, thus relieving the bearings from the friction incident to 
having the tension all on one side. 

The pulleys should be of as large a diameter as can be 
admitted, provided they will not produce a speed of more 
than 3,750 feet a minute. 

Pulleys should be a little wider than the belts required for 
the work. ) 

The motion of driving should run with^ and not against y 
the laps of the belts. 

In using tightening or guide pulleys, apply them to th« slack 
side of the belt and near the smallest pulley. Belts to run at 
high speed should be made as straight and uniform in section 
and density as possible; if practicable, make them endless; 
that is, with permanent joints, A loose running belt will last 
and wear longer than a tightly-drawn belt. Tightness is evi- 
dence of overwork and disproportion. Never add to the work 
of a belt so much as to overload it. 

The strongest part of a belt leather is near the flesh side, 
about one-eighth of the way through from that side. 

It is best to run the grain (or hair) side of the belt next to 
the pulley. 

The flesh side is not liable to crack, as the grain side will 
do when the belt is old ; hence, it is better to crimp the 
^rain instead oi stretching it. 

The grain side next to the pulley will give the belt thirty 
per cent, more power than if the flesh side was on the pulley. 

The belt, as well as the pulley adheres best when smooth, 
and the grain side is the smoother. 

A belt adheres much better and is less liable to slip when at 
a high speed than at a low speed. Therefore it is best to gear 
a mill with small pulleys and run them at high velocity, than 
v/ith large pulleys and to run them slower. Besides, the cost 
is less, and appearance much neater. 

Keep belts clear of grease and accumulation- of dust 
especially from contact with lubricating oil«»- 



»2 

Protect leather belts from water and moisture. 
Belts should be kept soft and pliable. 

i^ULES FOR CALCULATING THE HORSE-POWER WHICH CAN 
BE TRANSMITTED BY BELIING. 

To -^nd the horse -power a single b^lt can trans?uit, the size 
cf iJ:e pulley afid the width of the belt being given, — Multiply 
the diameter of the pulley in inches by the number of revolu- 
tions per minute; multiply this product by the width of the 
belt in inches, and divide by 2,750; the quotient will be the 
horse-power. 

For a doulle belt divide the last product by 1,925 instea(? 
of 2,750. 

The horse-power to he transinitted^ and the size of the pulley 
being knowit^to find the zvidth of the belt required. — Multiply 
the horse-power by 2.750 if the belt is single (by 1,925 if the 
belt is double); also multiply the diameter of the pulley in 
inches by the revolutions per minute. Divide the first prod- 
uct by the last, and the quotient will be the width of belt 
required. 

The horse-power and width of belt being known ^ to find the 
diajneter of the pulley, — Multiply the horse-power by 2,750 
for a single belt (or 1,925 if double); also multiply the revolu- 
tions per minute by the width in inches; divide the first prod- 
uct by the last, and the quotient will be the diameter of the 
pulley in Wches. 

The horse -power^ diameter of pulley and width of belt being 
known ^ to find the number of revolutions necessary. — Multiply 
the horse-power by the 2,750 if a single belt (1,925 if double); 
also multiply the diameter of the pulley in inches by the width 
of the belt in inches; divide the first product by the last, and 
tKe quotient will be the number of revolutions per minute 
required. 

it is assumed in these rules that the belts are open, and 
that the pulleys — both driver and driven — are of same 
diameter. If, however, the pulleys are of different diameters 
the smaller pulley will have less surface in contact with the 
belt than on the larger pulley. If this surface — called the 
arc of contact, is less than one-half the circumference, the 
above rules must be modified. In that case, instead ot using 
the numbers 2,750 for single belts, and 1,925 for double belts, 
use the following: When the arc of contact of the smaller 
pulley is 



83 

Single Double 

Belt. Belt. 

:!ic cireumference,. „ „ „ , 6,080 4,2f^ 

:: ;: -»- 4,730 3,3^;' 

O O O „...,. ., , . .4,400 3,080 

...«•-.= 3.850 2,700 

.' =• « 3,410 2,390 

..o. »,....... 3,220 2,250 

»'..»••.'»»•. 2,750 1,925 



TABLE SHOWING STRENGTH OF BEL'ITNG MATERIALS. 





Breaking 




Materials. 


Strain for i in. 
Wide. 


Thickness. 


Oak-tanned leather, _„„._.„ 


1,250 


1-4 in. 


Oak-tanned leather, „,,_..„<, 


1. 166 


1-4 in. 


Oak-tanned leather. , ....... . 


750 


1-4 in. 


Su2:ar-tanned leather. _ .. . . <, 


725 


1-4 in. 


Ordinary tanned leather , 


550 


3-16 in„ 


3-ply rubber, ....,,„„.„.„.„. 


1,000 


7-32 in= 


Cotton-duck. „ , . » . . „ „ . 


200 




Raw-hide ,,,„„.,.,.,„„,<,.,» „ 


958 


5-32 in. 


Flax_..„ „,.., „,„.,,.,.., 


1,489 





An examination of this table will show that it will be safe 
to estimate the breaking strain of leather and rubber belting 
at 4,000 pounds to the square inch of section, or i,ooo 
pounds to each inch of width. Cotton belting is usually laid 
4-ply forthe narrower widths, making, according to tables, a 
breaking strain of 800 pounds to the inch of width. This 
brings the three principal materials very near together. 

It is usual in allowing for the working strength of belts, to 
make the safe working strain i to 16 of the actual breaking 
strain, so that we have in this practice, 166 pounds as the 
working strain for leather and rubber to each one inch of 
widthp and 133 pounds for that of 4-ply cotton belting. 



^4 

FEED-WATER HEATERS. 

All water used in the generation of steam for mechanical pur- 
poses is more or less heavily impregnated with foreign matter 
held in solution; hme, magnesia, sulphur, iron, sihca, etc., or 
mud, sand and vegetable impurities held in suspension.^ 

Where ieed-water is pumped directly into boilers without 
first being purified, the heat used for generating steam sets 
free all impurities, and they are precipitated vpo^^ the innei 
sui-faces of the boiler in the form of scales or incrustation. 




This scale is a non-conductor of heat, and as it is inter- 
posed between the water and iron of the boiler, causes a 
? /eat deterioration of the boiler and corroding the iron. ^Q- 
.ades, the impurities in the water will cause priming and foam- 
ing, which injures the engine by allowing gnt to work into 
the cylinder, causing explosions, stoppages, delays and ex- 

pensive repairs. 4. .^ 

To eradicate these evils various solutions and patentea 

nostrums are introduced into the boiler; but this is a danger- 



»5 

ous and bad practice, as tlxe majority of them are not only 
valueless, but injurious. Sal-soda, however, makes a good 
purge y as it is called, and may be used with good effect where 
the water causes the boiler to prime or foam. 

It is more economical, however, to purify the water before 
it is fed into the boiler, and to this end, a good feed- water 
heater and filterer is necessary. 

The subject of feed-water heaters has not received much 
attention until within the last few years, but no plant is now 
considered complete without one. Besides purifying the 
water, the heater will increase the temperature of the water 
from its initial temperature to 200^ (in some heaters). This 
it does by means of the exhaust steam from the engine pass- 
ing through it, and every degree of temperature raised in the 
feed -water, is so much clear gain in economy of fuel, as the 
table on page 86 will show. e 

For instance,' if the feed- water enters the heater at 60° and 
is delivered to the boiler at 180^, there is a saving in fuel of 
10.46 per cent. If the feed-water enters the heater at 40^ 
and is delivered to the boiler at 200", the saving in fuel 
would be 13.71 per cent. 

The cut of the feed-water heater and purifier represents a 
standard heater called the Excelsior, made in Chicago, and 
heats the water up to 212^, or boihng point. 

It is thus readily seen that a saving of 13 per cent, in fuel 
by the use of a good feed- water heater is a matter of some con« 
siderable importance. A further saving, which cannot be so 
accurately calculated, is the save in the wear and tear of the 
boiler. The forcible injection of a stream of cold water into 
a highly heated vessel is bound to make a sudden variation 
in the degree of temperature, and any such variation is bound 
to affect the boiler to a greater or less extent. Where the 
water for steam purposes is drawn from the city pipes, the 
consumer is charged for the amount of water he uses, as 
measured by the water meter. This expense can be lowered 
fully 30 per cent, by using a feed-water heater, into which 
the exhaust of the engine passes. The steam is condensed 
and ib fed back into the boiler again, so that the water, in- 
stead of passing into the open air from the exhaust pipe, is 
collected and again made to do duty as steam. 

The feed-water heater should be placed in such a position 
as to be easily accessible on all sides, so that it can be readily 
and easily cleansed, and the sediment removed without dirty- 
ing up the engine or boiler room. 



< 
I 


Steam Pressure 6o Pounds. 


V 

V 

V 

o 

V 

u 

a 

OJ 

a 

V 


8| 


00 t^vo Tt r^. 

Gn Q^ 0^ C^* G^ 

O •-• ro vn !>. ON 


1 

1-4 


ON ON OnoO t^ t^ 
M CO uS t^ On •-< 


2: 


1 


ONOO i>.>0 i/~> '^ CO 


r- 
< 


t^iori o r^Tj-N On 
00 i>*vO i^ CO c>< O ON 

©•-t COlOt^ONi-I CO'^ 

l-l 1=1 l-=J 




% 

C^ 


'^ I^ C^ VO O LOOO C^ On 
OOnO lococ^ OOO X:^'^ 

O i-J coi-Ot>*ON>-i *••< ■^vd 

HH l-X r.H c- 1 


u 


8 


O *-* C^ CO CO --^ u-^ vovO 5^* 
OOVO TfC^ OOOVO "^M r 

O ►-J cOLOt^CNO' N rf vO °^ 

l-H hH l-l -H "^ 




8. 


O 00 t^vO vO i-O -^ CO N !-• t-< 

onno '^c^ ooovo '^^^^ ooo 

d C<i "^vo' 00 On ►-*' CO lO l>< 30 


o 

> 


0- 


l>-i-0(N ONt^i-OroO r-^w-ic^ 
r^u-iroOOOvO COC^ On1>-ij^ 

O »-i CO lO l>»00* d N Tj- to r^ On 

hH HH 1-4 M M l-l 


< 

CO 

c 


O 

o 


oo rj- Q Vo >-i oo CO OnvO i-" r^ <:"0 
00 VO ^ 1^ OnvO ""^ >-« ON r^ ""^ C^ 

d CS* "^vO X>. ON "-^ CO '^vo 00* d 




% 


TtONCOt-».MvO O O On ^00 C<J 
r^-^N ONJ>»Tfci Ovo '<^»-" ^ 

o "-H CO i^vd 00 d c4 Tfiot^dsd 




o 
o 


vO CNMi^t^O coo OC<iJ->l^^ 
O0vocoot^»^r< Oi:^'<^'-"00vo 

CO c^ -^vd !>. d- « CO ^vd 00* ON t-J 

„ ,«, HI hH H^ Ml M 


z 


o 


hH CO rt" VJ-) r-oo O >-* ^) coiovo r^ 
H-I CO Lovd 00 d ^i CO Lo r^oo d n 


Q 

in 


o 

CO 


ONONONOoo OO oonq ooo 

ro O r-^ >-0 N OnvO CO O t^ "^ >-' 00 
c4 r+- i-O I>- On O N ^vO r^ ON •-' N 


< 


JO 3amB4 




VO c8 8 8 §-vo 00 q <N ^o oo o 

1 



SETTING SLIDE-VALVES. 

We will suppose the engine to be new, and of the rocker 
type, and horizontal. 

First find in which direction the engine is co run. Set 
the crank on the forward dead-center by means of a square, 
or by a line. Be sure that it is oit the center. Set the eccen- 
tric at right angles to the crank, high side turned up. If the 
engine was to run the other way the eccentric would have to 
be turned down, or the engine turned on the other center. 

To get the eccentric accurately at right angles I use the 
following method: I get a planed board and fasten it wher- 
ever I can, at the eccentric side of the engine, in such n posi- 
tion that it will come under the eccentric rod. I put c*^ the 
straps and rods loosely. I then hold, or fasten a pencil to "h 
rod, and have an assistant turn the eccentric once aronr //, 
holding the pencil so it will mark the exact travel of the rod 
on the board. I find the center of this line with a pair of 
dividers or a rule. I turn the eccentric up until the })encil 
comes to the center of line. Fasten the eccentric loosely 
so it won't slip. It is now at right angles to the crank,' and 
in the neutral position. If the valve had no lap nor lead the 
eccentric would now be properly set. Next I find the exact 
center of the valve and mark it with a fine line in such a 
manner that the line will show on top of the valve. I also 
find the center of all the parts. I mark a fine line running 
up the side of steam-chest so it can be seen above the 
valve. I then place the valve over the parts, and bring 
line on valve and line on steam-chest, so they are together 
This puts the valve in its central or neutral position. I 
put in the rod and connect it to rocker-arm. I })lumb 
the rocker with a plumb-line and bob so that the center of 
eccentric rod-pin will be cut by the line, and screw jamb-nuts 
up to the valve with my fingers. I now fasten the valve so 
it can't move. That is, if I can, without too much trouble. 
Valve, rocker and eccentric are now in the neutral position, 
and temporarily fastened. The eccentric- rod must now be 
brought into such a position that it will hook onto the 
rocker-arm without moving it a hair's breadth. I now turn 
the eccentric the way the engine is to run until I have the 
proper lead or opening. If I have been accurate in my work 
the valve is properly set. To prove it I put the engine on 
the other center, and if the lead is the same I fasten every- 
thing. The valve is set. The distance I turned the e'^rentric 



88 

from a right angle with the crank is known as the angle of 
advance. 

POINTS ON BOILER'S CIRCUMFERENCE. 
In text-books we have the areas and circumferences of 
circles, but if we don't know how to use them, they are of no 
use to us. They are all right for tin or any thin stuff, but 
not for boiler-makers. As an instance, supposing we have a 
boiler to make 36" diameter. If we look at the table of cir- 
cumference we will find that it takes 113.098" — one hundred 
and thirteen inches and about one-sixteenth. This would not 
give either side or outside diameter, but would be the thick- 
ness of iron, less, if we were wanting inside measurement, or 
more, if for outside diameter. If the shell is of j^^" material we 
must add the X' to the diameter for inside diameter, making 
it 36X"- For this we will find that it takes 113.883" or a 
little over | of an inch more, and for outside diameter we 
must take off the thickness of material, making the diameter 
2SH"' ^"or this it would take 1 12.312", or about 113^4^, as 
near as can be got by the common rule. There are several 
ways for figuring this. My plan is to multiply the diameter 
by three, and divide the same by seven, and add the product 
together. But it must be understood that neither this or the 
taking from tables in text-books gives laps. In working this 
rule, three times ^6% is 1083.4^, and 7 into 36 will go 5 times 
and 1 over, but instead of calling it ^ call it i, and we have it 
on the rule. For the small course there is a difference of six 
and one-half times the thickness of material. This will hold 
good in all cases, so that if we get one course out by figuring, 
the other maybe got by adding or subtracting this difference. 
As in the majority of men, they have a holy horror of figures, 
especially boiler-makers, in "manufactories." Another thing 
that is not generally understood among them is the properties 
of a circle. A circular vessel will contain a greater quantity 
than a vessel of any other shape, made of the same amount 
of material. That is to say, if an iron plate, six feet long, 
was rolled to a circle and a bottom put in it, it would hold 
more water than if it was bent square or any other shape. 
The areas of circles are to each other as the squares of their 
diameters. Any circle twice the diameter of another, is 
also four times its area and twice its circumference. *" The 
diameter of a circle is a straight line drawn through its 
center, touching both sides. The radius of a circle is half the 
diameter, or the distance fro^ the center to the circumference. 



89 

HOW TO SET A LOCOMOTIVE ECCENTRIC. 

I am familiar with the rule for setting a slipped eccentric 
by placing engine on center and marking the stem 
by using the eccentric that is not slipped, for a guide, but 
what I want is a rule to set a slipped eccentric without 
another to go by; suppose I slip both eccentrics on the right 
side, what am I to do, and why should I do it? A. — If both 
eccentrics on a side slip stop at once, protect your train, and 
be sure the eccentrics are slipped, before you go to work on 
them; if they are "off" beyond a doubt, take off the chest 
cover and pinch the engine onto the center (no matter which 
center), take the eccentric next the box first, as you can get the 
other out of the way to work at it; if this is the go-ahead ec- 
centric, place the reverse lever in forward notch and turn 
the eccentric around on the shaft ahead until the port 
opens ^-^o" <^r q" •> the amount of lead you want, and fasten it 
there; put the reverse lever in the back notch and turn the 
back-up eccentric back until the port is open, the same as it 
was with the go-ahead, and fasten eccentric Where only one 
eccentric it slipped, it is best to set it by marking the stem; 
that plan is the quickest, as you do not have to take off the 
cover. You will readily see that when one side is on /''.le 
center, the engine will go either way, as steam is adm^ -^- to 
one side or the other of the piston on the other sir* - Q^ locQ« 
motive, as it is in the center of cylinder, and by Cuting the 
eccentrics to give lead on the center, and by ti. xiing them 
the right way, you can't get them wrong. A goo\.' engineer: 
will always save himself all this trouble and delay on 'ch.Q rocA 
by marking the eccentrics in their proper position, L '^ ^ ?.s 
running a locomotive without eccentric keys. 

CHIMNEYS. 

The following table shows the proportion of sizes of chim 
neys to the horse-power of the boiler using the chimney. 
The measurements givnn for the diameter is for ?;//^'r;?^/ diam- 
eter. By referring back to the article on " Steam Boilers" 
commencing at page 45, the rules given for firegrate surface 
can be utilized in connection with this table in planning for 
the steam power of a plant. This table has been carefully 
compiled and arranged, and the proportions given may be 
accepted as correct. Too little attention is paid to chimneys, 
and the furnace is often blamed for poor resuhs wlien the 
ckimney is the part in wrong. Proper draught is all-import- 
ant, and one chimnf^"- should never be made to do the work 
of two 



^ 



o 

pa 

U^ 
O 

(^ 

w 
o 

Oh 

w 

p^ 

O 

w 
o 

PLh 

< 

H 
I— I 

>^ 

W 

l-H 

u 
o 

CD 

W 
N 

C/2 



•5J sJBnbs 

Bsjy 

IBnioy 


N. M Ti-OO H '^^ t^ N tv. ThVO t^OO 00 00 t^ 
t>. Tj- w O^ 0\ (y, mvO IT) o\vo t^ N w •* >-" N 

H N ro CO -^ u-i t^oo 0^ N lA ON rooo rnoo' 4- O 


•ysjBnbg 
B9jy 

3Al5D3jgg 


c^ t^oo 00 00 00 r^ tv.vo -* m oo rooo mvo o m 

^■^0 t^lOrfTi-lOt^Tl-iO ooo t^ t^ •-> 


•-< W « CO -^ lOvO l> rovo lo ON 'i- vo 
Hi-iiHC>)W0»rO'^-<i- 


•saqouT 
SJBnbs 
JO apig 


VO O^ PJ ^ t«» N trioo moo '^ On •* ir> ^ 
H M 01 c* N rororocoTi-Tj-io lo^o c^ t^-;o oo 


1— « 
U 

Pi 

8 
<l 

c/: pH 

o 

O 

l-H 

w 


^ 


M M t^ <^ t^ 

00 00 rn OnvO 
On i-i '^•vO 00 "H 

M M M w w 




00 00 in M t^ 

>* M w fo t^ N 
t^ On f-i CO lO r^ 

w M « M M 


i-i 


M N Os en a oo o^vo 
muD 00 (N T)-vo 00 

M M ., M M 


i 


0> CO (N vO ■* t^ -*vO 
00 o cot^roo OnOn 
CO mo t^ On iH N ■<*- 





M ID N COOO VO 00 Th 
t^vo r>« On (N t^ ro 1- 
w CO -^ m t>.oo w 


8 


f^ O^OO oo On to r(- »r> 
OOw LO-^Tj-vO OnCO 
•- (N C4 CO ^ lOvO 00 


a 


CO M COOO lO t^O 
HI -^t^O -^roo) CO 

WHMWNCOTtl/, 




C) CO t^ CO COVO M M 

VO 00 O COvO ON CO -. 

W M M I-I M CO 




c^ M 00 oo in N COVO 
w -"I- in c^ w inoo w 


v8 


inoo Ti- « N in M 
M CO m t^ On H Tf 

1-4 HI 




CO in On in ■* 

OJ CO -^NOOO 


•saqou 


I UI 
Bid 


00 M f t^ O fO<o Onnoo -rf O noo tJ-OvO 
-HNWWfOcoroco-"*--"*- mvo vo t^ t^oo on o\ 



i s 

S Ji 

>» CO 

5* <u CO 

^ 2 ^-^ 

^ o-rr 

:= (u -^ S 



o P 



o o 



u <fl 



V (u on"" 

^--^^ 



D, -, 'O 



'^ rt r «L» 
*-» j-i 5 4» 

<^ - v> 



03 



91 
DEFINITIONS AND USEFUL NUMBERS. 

ARITHMEIICAL SIGNS USED IN THIS BOOK. 

+ Plus, or more, the sign of addition, as 2 + 2 = 4. 
" — Minus, or less, the sign of subtraction, as 4 — 2 =2. 
X signifies multiplied into or by-, as 3 X 3 .= 9. 
-f- signifies divided by, as 10 -^ 5 = 2. 
= signifies equality, or equal to, as 4 + 4 = S. 
: :: :, the sign of proportion, as 2 ; 4 :: 3 : 6; which reads 
thus: as 2 is to 4 so is 3 to 6. [j 

y , the sign of the square root, as ^^49 = 7; that is. 7 is 
the square root of 49, or 7 is the number which, if multi- 
plied by itself, produces 49. 

7^ means the square of 7, or that 7 is to be squared or multi- 
plied by itself. The square of any number is the product 
of the number multiplied by itself. 

73 means the cube of 7, or that 7 is to be multiplied by 7, 
and again by 7. The cibe of any number is the product 
of that number multiplied by itself, and again by itself ' 

S ^UARE MEASURE AND CUBIC MEASURE. 

144 square inches = I square foot. 
9 square feet = i square yard. 
] 728 cubic inches = i cubic foot. 
27 cubic feet = i cubic yard. 

DEFINITIONS OF TERMS WHICH ARE EMPLOYED IN THE 
FOLLOWING RULES. 

A c ^ A Point has a position witliout mag- 

nitude, as at C, Fig. i. 

6 E F A Line has length without breadth, 

Figs. 1 and 2. as D E, Fig. 2. 

Right Line is the shortest ( 
between any two points, r P, Fig. 3. 



A Right Line is the shortest distance £_ J; 

Fig.3. 



A Superficies has length and breadth only. 
Fig. 4. 



Fig. 4. 



92 



Fig. 9. 



A Solid has length, breadth and thickness. 
Fig- S- 

An Angle is the opening of two lines hav- 
ing different directions, and is either Right, 
Acute, or Obtuse. 



A Right Angle is made by a line being drawn 
perpendicular to another, as in Fig. 6. «■ 



Fig. 6. 



7. 



An Acute Angle is less than a Right Angle„ 
Fig. 7. 



An Obtuse Angle is greater than a Right 
Angle. Fig. 8. 



Fig. 8 



A Triangle is a figure bounded by three straight lines. 
Figs. 9, 10, II. 




Tig. 9. 



An Equilateral Triangle is a Triangle of which the 
three sides are equal to each other. Fig. 9. 



An Is<^sceles Triangle has tv/o of its sides equal. 
Fig. 10. 




Fig. 10, 




A Scalene Triangle has all its sides unequal. 



Fig. II. 



Fig. 11. 



93 



A Right-angled Triangle has one Right Angle. 
Fig. 12. 



Fig. 12- 

A Square is a 4-sided figure having all its sides 
equal, and all its angles Right Angles. Fig. 13. 




Fig. 13. 
A Rectangle is a 4-sided figure, having its 
angles Right Angles, and of which the length 
_ _ exceeds its breadth. Fig. 14. 

±'ig. 14. 
An Arc is any part of the circum- 
ference of a circle, as A c B, Fig. 

A Chord is a right line joining 
the extremities of an Arc, as A B, 

Fig. 15- 

A Segment of a Circle is any part 
bounded by an Arc and its Chord, 
as the Segment A c B, Fig. 15. 

A Diameter is a straight line 
passing through the center of a 
Circle, and bounded by the circum- 
ference at both ends, asG h. Fig. 15. 

A Semicircle is half a Circle, as G c H, Fig. 15. 

The Circumference of a Circle is the outside boundary line 
described on the center with a length equal to the radius. 

A Quadrant is a Quarter Circle, as G o i. Fig. 15. 

A Tangent is a Right Line that touches a Circle without 
B cutting it, as E F, Fig. 15. 



B Concentric Circles are Circles hav- 
ing the same center, and the space 
included between their circumfer- 
ences is called a Ring. Fig. 16. 



Fig. 15. 




Fig. 16. 



94 



USEFUL NUMBERS IN CALCULATION. 



Lbs. Pounds 

Diameter of Circle 
Circumference 
Cubic inches 
Cubic feet 
Cylindrical in. 
Cylindrical feet 
Diameter of circle 
Side of a square 

Square of the } 
diameter f 
Radius of circle 
Cubic inches 
Cylindrical inches 
Cubic ft. of water 
Gallons of water 



X 
X 
X 
X 
X 
X. 
X 
X 
X 
X 

X 
X 



.009 


= Hundredweights. 


.00045 


=T Tons. 


3.I4I6 


= Circumference. 


•3183 


= Diameter. 


.003607 


= Gallons. 


6.232 


= Gallons. 


.002832 


= Gallons. 


4.895 


= Gallons. 


.88622 


= Side of equal sq. 


1. 128 


= Diam. of circle of 




equal area. 


.7854 


= Area of circle. 


6.2831 


= Circumference. 


277.274 


= Gallons. 


353-03 


= Gallons. 


35.9 


=- Tons. 


10 


= Pounds weight. 



MENSURATION. 

To find the circ'iivifere7ice of a circle when the diameter is 
given. — Multiply the diameter by 3.1416; the product is the 
circumference. 

A common method of calculating the circumference is to 
multiply the diameter by 3, and add \ of the diameter to the 
product. The sum is the circumference, very nearly. Or, 
what amounts to the same thing, multiply the diameter by 
22, and divide the product by 7. 

Another method of finding the circumference is to multi- 
ply the diameter by 3, and add -fg- inch to the product for 
every foot-length in the product. The reason for adding -fg 
inch for each foot of the product, is, that it is the same in 
effect as the addition of I of the diameter. As the product 
is equal to three times the diameter, the addition to be made 
per foot of product should be only a third of the addition 
per foot of diameter; that is, instead of } of the diameter 
the addition is j- 
rate of -i^jj inch per foot of the product. 

To find the diameter of a circle when the circumfer- 
ence is given — Multiply the length of the circumference by 
the decimal .3183; the product is the diameter. 



3 of 7, or 2T of the product, which is at the 



95 

Or, divide the circumference by 3.1416; the quotient 
is the diameter. 

Or, multiply the circumference by 7, and divide the 
product by 22; the quotient is the diameter, very nearly. 

To find the area of a circle. - Square the diamreter — that 
is to say, multiply the diameter by itself, say, in inches 
— and multiply the product by the decimal .7854. The 
product is the area of the circle in ^ 

square inches. 

To find the length of an arc of a 
circle. — From 8 times the chord, a 
D, Fig. 17, of half the arc A D E, 
subtract the chord of the whole arc, 
A E, and divide the remainder by 3. 
The quotient is the eighth of the 
arc, nearly. ^ 

I5g. 17. 

To fi7id the diameter when the chord of an 
arc and the versed si^te are given. — Divide 
the square of half the chord by the versed 
sine, and to the product add the versed 
sine. The sum ?.s the diameter. 
Note. — The versed sine is the height of the 

arc. 

rea of a segment of a ring. 





A^ 





Fig. 18. 
/o find the ^ . _ 

- 'Multiply half the" sum of the bounding 
-ires by their distance apart; the product 
is the area. Thus, let the arc A x D be 90 
inches long, and the arc B C4f) inches long, 
and the distance a B or C D iSinc/ieslong; 
then 90" + 40" = 130; and 130 -^ 2 == 
65; and 65 X 18'' = 1 1 70 square inches, 
the area. 

To find the a^'ea of a :iegment of a circle. — To % of the 
product of the chord a b and versed ine 
c D of the segment, add the cube of 
the versed sine divided by twice the 
chord; and the sum is the area, nearly. 
Thus — 

Given the chord a B as 20 inches, and 

Fig. 20. the versed sine 3 inches; recjuired the 

area. 20 X 3 = 60; and 60 X 2 -^ 3 

-= 40. Then 3 inches cubed =3 X3 X3 = 9X3=27; 




96 




and 27 -T- (20 X 2) = .675; and .675 + 40 = 40.675 = area 
nearly. 

When the segment is greater than a semicircle, find the 
area of the remaining segment and deduct it from the area 
of the whole circle, the remainder is the area of the seg- 
ment. 

To find the area of a sector of a circle. — Multiply half the 
length of the arc by the radius of the circle. The product is 
the area of the sector. See Fig. 17. 

To find the cifcti77iference of an ellipse. — Add the two dia- 
meters together; divide the sum by 2, 
and multiply the quotient by 3. 1416. 
Or, multiply the sum of the two dia- 
meters by 1.5708. The product in 
either process, is the circumference, 
nearly. Thus — what is the circumfer- 
ence of an ellipse of which the diameters 
are 10 and 14? 14 + 10 = 24; and 24 
X i«57o8 = 37-6992; or, 10 + 14 = 24; and 24 -f- 2 = 12; 
and 12 X 3.1416= 37.6992 = the circumference of the 
ellipse. 

To find the area of an ellipse. — Multiply the two diameters 
together, and multiply the product by .7854. The final 
product is the area. 

Tofifidthe area of a square. — Multiply the length of one 
side by itself, or square the side. The product is the area. 
For example, a square has each side 12 inches long; what is 
the area? 12 X 12= 144 square inches is the area of the 
square. 

To find the area of a rectangle. — Lvlultiply the length by 
the breadth; the product is the area. For example, a rect- 
angular plate is 24 inches long and 12 inches wide; what is 
the area? 24 X 12 = 288 square inches. 

To find the cubic content of a rectangular or cubical body. -^ 
Multiply the length by the breadth, 
and multiply the product by the depth. \ 
The last product is the cubic content, ^fk 
For example, a box or cistern is 5 feet j 
long, 2^2 feet wide, and 3 feet deep; ^ 
what is the cubic content? 5 feet mul- 
tiplied by 25^ feet makes an area of 22. 
12^ square feet; and 12^ feet multiplied by three is equal 
to 37^ cubic feet. 



X 




[M^ 










x 




\ 





9/ 



To find the cubic content of a square-ended cylinder,'-^ 
/ind the area of one end by the rule for the area of a circle, 
and multiply the area by the length. The product is tlie 
Rubic content of the cylinder. 




30' 




•Pig. 23. 

Note, — The dimensions are to be taken all in inches or ali 
feet. The square measure and the cubic measure^ corres- 
pondingly, will be in inches or in feet. 

Exa7nple. — A cylinder is 22 inches in diameter and 36 
inches in length; what is the cubic content? 
22 inches. .7854 
22 484 



— 380. 1336 square inches, area of the end. 



44 


31416 


44 


62832 




31416 


484 






380-1336 




36 




22808016 




I 1404008 



13684.8096 cubic inches, solid content. 




B 



D 

Fig. 24 
may be calculated by squaring the side 
by 4, and multiplying by 1.732 



To find the area of a trt* 
angle. — Multiply the length 
of the base a b by the perpen- 
dicular height c D, and divide 
the product by 2. The quo- 
tient is the area of the tri- 
angle. 

When the triangle is equi- 
lateral, or equal sided, the area 
dividing the square 



98 

To find the cubic content of a sphere. — Multiply the cube 
of the diameter by the decimal .5236; the product is the 
cubic content. For example, let the diameter be 12 inches. 
The cube of 12, or 12 X 12 X 12 = 1728, and 1728 X .5236 
= 904.78 cubic inches. 

To find the content of a segment of a sphei-e. — Square the 
radius, or half diameter, of the base, and multiply the square 
by 3. To the product add the square of the height of the 
segment, and multiply the sum by the height and by the 
decimal .5236. The product is the content of the segment. 

To find the content of a frustuvi of a cone. — Square the 
diameter of each end, and multiply one diameter by the 
other ; add together the two squares and the product, and 
multiply the sum by the height of the frustum and by 
.2618. The final product is the concent. 

To find the content of a friLsttun of a square pyramid, — 
Add together the areas of the two ends and the product of 
the lengths of side of the ends; multiply the sum of the 
height, and divide the product by 3. 

PRACTICAL GEOMETRY FOR MECHANICS, EN- 
GINEERS, BOILER-MAKERS, ETC. 

To bisect a given right line. — That is, to divide it, or 
square it across in two 
equal parts. Let A B, Fig. 
25, be the given right line. 



r5> 



./ 



Av- 



( 

r 

> , 

I 
\ 
\ 



/^^-^ 



B 



IB 



i'D 



Fiff 26. 
^ Fig. 25. 

Then, with any radius greater than a e — that is greater than 
half the length of the line — and on A and B, as centers, de- 
scribe two arcs cutting each other at C and D, draw the hne 
C E D through the intersections. Then c E D will be at right 
angles to A E, and the line A B is divided into two equal 
parts at E. 



99 

To draw a perpendicular to a. straight line from one of 
its extremities, — Let A B, Fig. 26, be the given line, and B the 
extremity from which the perpendicular is to be drawn. Take 
any point, C, and with the radius C B describe an arc of a 
circle, A B D; draw a line from A, through c, cutting the arc 
at D; then, a line drawn through the intersection at D 
from B will be perpendicular to A B. 

To drdiv a perpendicular to a right line from a point with- 
out the line; that is, 
when the point is not 

on the line. Let A B, 
Fig. 27, be the given 
line, and C the point 
through which the per- 
pendicular is to be 
.jj drawn. Then, on c as 



^. 



"" I '' 2 a center, with any radi- 

I us greater than the dis- 

j tance to the line A B, 

I describe an arc cutting 

\}y' A B at E and D; and on 

^^'^K E and D as centers, with 

p. „- any radius greater than 

^* E D, describe two arcs 

cutting each other at F 

£; a line drawn through F and C will be perpendicular to A B. 

To draw a line parallel to 
E y ^ I' a given sti'aight line. — First, 

*^*''" --- .■--'""'-'-;; to draw the parallel at a giv- 

en distance. Let A B, Fig. 
28, be the given line. Open 

—I t the compasses to the distance 

C 3> required, and from any two 

Fig. 28. points, c and D, describe arcs 

E and F. Draw the line G H, 
touching tlie arcs. It is the required parallel. 

Q c 5— jj Second, to draw a parallel 

/ ^"-^ ; through a given point. Let c, 

/ ^^-v^^ / Fig. 29, be the point. From 

I ''--. / C draw any line C D to A B. 

A— ^Jt" ^ B On C D, as centers, describe 

„. arcs D E and c F. Cut off i) E 

equal to c F, and through the 
points C and E draw the parallel G 11. 



loo 



X 



To draw a rectangle from the center lines. — Draw the line 
A B, Fig. 30, equal to one of the center lines, bisect it 
// £ C ^^ ^' draw the other 

- center line, D E, 
through c, at right 
angles to A B; then 
with c D as a radius, 
and on B and A as 

« centers, d e s cr i b e 
arcs at H, j, F, and 
g; again with C A 
as radius, on E and 
D as centers, de- 
scribe arcs cutting 

- the arcs at H, j, F, 
'"and G. Join the 

i n t e t s e ctions by 




D 

Fig. 30. 

straight lines, these will be at right angles and will form a 
rectangle. 

To draw a square on a given 
line. — Let A B, Fig. 31, be the 
given line. Erect a perpendicu- 
lar at B, and on B as a center, 
with B A as a radius, describe an 
arc at D, and on D as a center 
describe another arc at c. On A 
as a center, with the same radius 
describe an arc cutting the other 
arc at C. Join the intersections ri{?. 31. 

by straight lines, and the square 

is formed. If truly square, it should measure the same length 
in the two diagonal directions; that is, the distance A d should 
be equal to the distance B c. a 



To bisect an a7igle. — That is, to divide 
it in two equal angles. On the point of 
the angle. A, Fig. 32, as a center, with 
any radius, describe an arc cutting the 
sides of the angle at D and E, and on D and 
E as centers, describe two arcs cutting each 
other at F. The line drawn through A and 
2" will bisect the angle. 




lOI 



..€,.-' 




Upon a given right line to const?'tici 
an equilateral triangle. — Let A. B, Fig. 
33, be the given right hne; then on A 
and B, with A B as radius, describe two 
arcs cutting each other at C, join A C 
and B c, and the triangle ABC, thus 
formed, is an equilateral triangle. 



rig. 33. 




In a given circle to i^iscrihe a 
sqnai-e. — Draw any two diameters at 
right angles to each other, and join 
the extremities, as in Fig. 34.^ 

To inscribe an octgcgon. — First in- 
scribe the square, then bisect the 
quarter circles and join the extremi- 
ties. Or, bisect the angle A O D, Fig. 
34, by the line o F. Then D F is the 
length of tbe side of the octagon. 

Fisf. '^4. 

To draw a 'circle through three given points, no matter how 
they may are placed. — 
This is a very useful 
problem, as it enables 
any one to determine 
the diameter of the circle 
of which an arc is a part. 
Place the three points, 
I, 2, 3, anywhere. With 
any radius greater than 
half the distance ^ be- 
tween two of the points, 
I and 2, and on these 
points as centers, de- 
scribe two arcs cutting 
each other at A and B. 
Similarly, describe in- 
tersecting arcs on the 
points 2 and 3 as cen- 
ters. Draw straight lines through the mtersections respect- 
ively, meeting at^O. Then o is the center from which the 
arc is to be described, with the radius o I, which will pass 
through all the three points. 




Fig. 35. 



I02 




To draw a straight une equal in length to a given arc of 
a circle. — Divide the chord A B into 

four equal parts; set off one of these ^^^ --^C 

parts from B to c, and join c D. The 
line C D is equal to the length of half 
the given arc nearly. Fig. 36. 

To describe a rectangle wheii the length of the diagonal 
and that cf one of the ends is gii'cn. — Draw tlie diagonal 
A B. Bisect it at the center o, and with o a as radius, 
describe a circle. Set off the length of the end from a, cut- 
ting the circle at D, and from B cutting the circle at C, and 
ioin A C, C B, B D, and D a, to form the rectangle required. 




^&- 37, Fig 38. 

To cojistriict a square whose diagonal only is givejio — 
Divide the diagonal into seventeen ec[ual parts. Twelve of 
these parts are the measure of the side of the square. From 
A take up twelve parts in the compasses, and draw arcs of a 
circle at B and at C; and on d as a center^ with the same 

radius, draw arcs, cutting those at 
C and D, and join the intersec- 
tions to form the square A B D c. 

Another viethod. — Bisect the 
diagonal at O, by the perpendicular 
line c D; and on the center o and 
with the radius o B, describe arcs 
at c and D. Join the intersections 
to form the square A C B D. 

To draiv a square equal in area 

to a given ciirle. — D ivi de t h e diame - 

ter A B into fourteen equal parts: 

^^fiT* 39. set off eleven of these from A to o. 




I03 

and from o draw the perpendicular o c, cutting the circle at 
c; and draw A c. Then A c is the side of a square of which 
the area is equal to that of the circle. To complete the square, 

from C draw a line 
through the center 
of the circle, cutting 
the c i re um f e r e n ce 
at E; and from A 
draw the straight line 
A E F, through the 
point E. This line is 
at right angles to A C. 
With the radius A c, 
and on A as a center, 
describe arj arc at F ; 
Cand on F, with the 
same radius, draw an 
arc at G. From c, 
again, draw an arc 
cutting the former at 
G with the same 'ra- 
dius. Join the ia- 
iersections, and the 
square is completed, 
circle by .886226: the 




Fig. 40. 



Or, multiply the diameter of the 
product is the side of a square of equal area. 

To ih-aw a square equal in area to a given triangle. — Let 
B P A be the given triangle. Draw the perpendicular p c 
from the summit P, and bisect it. Produce the side of the 

triangle B a, and 
set off A E equal to 
the half of p c. 
Divide E b into 
two equal parts at 
D; and on D as 
center, with d B as 
radius, describe 
the semicircle e b. 
Draw the perpen- 
dicular A F, cutting 




£ i4 



O C 

Fig. 41. 

the circle at F; then A F is the side of a square equal in area 
to that of the given triangle. 



I04 ' 

Another method. — A right-angled triangle being given, 
to construct a square of the same area. Divide the diagonal 
into thirty-four equal parts ; set off ten of these parts from 




Fig. 42. 
A, ana ten from B, leaving fourteen in the middle. Draw G C 
and G E through the ten divisions, parallel to F E and c F 
respectively. The square c F E G has an area equal to that 
of the triangle A B F. 

To produce a circle equal in area to a given square, — . 
Given the square A b c D; draw the diagonals and divide 




A -^ B 

Fig. 43. 
half a diagonal, o c, into fifteen equal parts. On o as 
center, and with a radius of twelve of these parts, describe 
a circle. This circle is of the same area as the square. 

Or, multiply the side of the square by 1. 12837. The prod- 
uct is the diameter of a circle equal in area to the square of 
which the side is given. 



505 



D 






C 


/ 


/ 


B 


/ / 


'/ 


^ -''' / 



The square is divided 
into four triangles, each of 
which IS one-fourth of the 
square in area. The quar- 
ter circles, whose figures 
differ of course materially/ 
from those of the triangles, 
have each the same area as 
one of the triangles. 

To find the side of a 
square which shall con- 
tain the area of a given 
squa7'e any even mimber 
of times, — Draw the given 
^ H ^ E square A E. The diagonal 

^*ff- 44. ' F G is the side of a square 

of double the area of the given square. Set-off E H, equal to 

the diagonal F G; then 
the square E B has four 
times the area of the 
given square. Set-off 
again e i, equal to the 
diagonal H J of t h e 
square EB, and draw the 
square E C on that base; 
the square E c has twice 
the area of E B, or four 
tm":es that of the square 
E A. Set off E L equal to 
erected on that base, has 
twice the area of E C. 
And so on. 

To dj'aw an ellipse 
approximately^ of a 
given leftgth without 
regard to breadth.- — 
Divide the given 
length into three equal 
parts at o and V; and 
on o and V as centers, 
with A O as radius, 
describe two circles 
cutting each other at 
I and Kon I and K as 




Fig. 45. 
the diagonal i K; the square E D, 
c 




Fig. 46ib 



io6 

with the diameter of the circle A o v as radius, describe 
centers arci; D E F g, to complete the form of an ellipse. 

If the radius of the ends is too large and flat, divide the 
given length into four equal parts, Fig. 45A, and describe 
three circles as shov^^n; and on H and F as centers, describe 
the lateral arcs to touch the first and third circles, and so 
complete the figure. 

To di'aio an ellipse when the length and breadth are given 
— Draw the diametrical lines at right angles to each other, 
intersecting at O. . Set out the length and breadth of the 
figure on these lines equally from the center o. Set off the 
length O D with the compasses on tlie longer diameter from 
x^ ^r^ ^^ and on o as a center, with the radius o E, desc^ihe the 




Fig 46. 

quadrant E F. Draw the line or chord E F, and set off the 
half of it from E to G. On o as a center, with o G as radius, 
describe the circle G H j i; then i and G are the centers for 
the segmental arcs at A and B, and H and j are the centers for 
the latf^'-^V arcs at c and d. 



I07 



TABLK OF SQUARE AND CUBE ROOTS, 



^^ 


















No. 


Square 


Cube 


No. 


Square 


Cube 


No. 

1 
42 


Square 


Cube 


Root. 
I . 


Root. 


Root. 


Root. 


Root. 


Root. 


I 




6 


2.449 


1. 817 


6.481 


3-476 


1-16 


1-031 


1.020 


1-4 


2.5 


1.832 


43 


6-557 


3-503 


1-8 


1.060 


1 .040 


1-2 


2-550 


1.866 


44 


6.633 


3-530 


3-16 


1.089 


1.059 


3-4 


2 - 599 


1.890 


45 


6.708 


3-557 


1-4 


1.118 


1.077 


7 


2.646 


1-9^3 


46 


6.782 


3-583 


5-16 


1.146 


1.095 


1-4 


2 .692 


1 • 935 


47 


6.856 


3-609 


3-8 


1-173 


1. 112 


1-2 


2-739 


1-957 


48 


6.928 


3-634 


7-16 


1.199 


1.129 


3-4 


2.784 


1.979 


49 


7- 


3-659 


1-2 


1.225 


1-145 


8 


2.828 


2. 


50 


7.071 


3-684 


9-16 


1.250 


1.161 


1-4 


2.872 


2.021 


51 


7.141 


3.708 


5-8 


1-275 


1.176 


1-2 


2.915 


2.041 


52 


7.211 


3-733 


11-16 


1.299 


1-191 


3-4 


2.958 


2.061 


53 


7.280 


3-756 


3-4 


1-323 


1.205 


9 


3- 


2.080 


54 


7-348 


3-780 


13-16 


1.346 


1.219 


1-4 


3.041 


2.098 


55 


7.416 


3 803 


7-8 


1.369 


1-233 


1-2 


3.682 


2. 118 


56 


7-483 


3.826 


15-^6 


1.392 


1.247 


3-4 


3.122 


2.136 


57 


7-550 


3-849 


2 


1.414 


1.260 


10 


3-162 


2.154 


58 


7.616 


3-871 


1-16 


1.436 


1.273 


11 


3-317 


2.224 


59 


7.681 


3 '895 


1-8 


1.458 


1.286 


12 


3-464 


2.289 


60 


7.746 


3-9^5 


3-16 


1.479 


1.298 


13 


3.606 


2.351 


61 


7.810 


3-937 


1-4 


1.5 


1-310 


14 


3-742 


2.410 


62 


7.874 


3-958 


s-^^. 


1. 521 


1 . 322 


T-S 


3-873 


2.A66 


63 


7-937 


3-97Q 


3-8 


1-541 


^•334 


16 


4- 


2 . s20 


64 


8. 


4- 


7-16 


1.561 


1.346 


17 


4-123 


2-57^ 


65 


8.062 


4.021 


1-2 


1.581 


1-358 


18 


4-243 


2. 621 


66 


8.124 


4.041 


9-16 


1.600 


1.369 


19 


4-359 


2.668 


^1 


8.185 


4.061 


5-8 


1.620 


1.3S0 


20 


4-472 


2.714 


68 


8.246 


4.082 


11-16 


1-639 


I -391 


21 


4-583 


2.759 


69 


8.307 


4.102 


3-4 


1.658 


1-402 


22 


4.690 


2.802 


70 


8.367 


4.121 


13-16 


1.677 


I -412 


23 


4.796 


2.844 


71 


8.426 


4.141 


7-8 


1.695 


1.422 


24 


4.899 


2.885 


72 


8.485 


4.160 


15-16 


1.714 


1-432 


25 


5. 


2.924 


73 


8-544 


4.179 


3 


1.732 


1.442 


26 


5-099 


2.963 


74 


8.602 


4.198 


1-8 


1.768 


1.462 


27 


5.196 


3- 


75 


8.660 


4.217 


1-4 


1.803 


1.482 


28 


5-292 


3-037 


76 


8.718 


4.236 


3-8 


1-837 


^•5 


29 


5.385 


3-072 


77 


8-775 


4-254 


1-2 


1.871 


1-518 


30 


5-477 


3.107 


78 


8.832 


4-273 


5-8 


1.904 


1-535 


31 


5.568 


3-141 


79 


8.888 


4.291 


3-4 


1.936 


1-553 


32 


5-657 


3-175 


80 


8.944 


4-309 


7-8 


1.968 


1-570 


33 


5-745 


3.208 


8i 


9- 


4 .327 


4 


2. 


1.587 


34 


5.831 


3.240 


82 


9.056 


4 -.345 


1-4 


2.o6i 


1-6x9 


35 


5.916 


3.271 


83 


9. no 


4.362 


1-2 


2.121 


1-651 


36 


6. 


3-302 


84 


9.165 


4-379 


3-4 


2.179 


i-68i 


37 


6.083 


3 • 332 


85 


9.220 


4-397 


5 


2.236 


1.710 


38 


6.164 


3-362 


86 


9.274 


4.414 


1-4 


2.291 


1.738 


39 


6.245 


3-391 


87 


9.327 


4-431 


I--2 


2-345 


1.765 


40 


6.325 


3.420 


88 


9.381 


4-448 


3-4 


2 398 


1.792 


41 


6.403 


3 448 


89 


9-434 


4-465 



io5 



Table of 


Square and Cube Roots.— 


Continued, 


No. 


Square 


Cube 


No. 
138 


Square 


Cube 


No. 


Square 


Cube 


Root. 


Root. 


Root 


Root. 


Root. 


Root. 


$o 


9.487 


4.481 


11.747 


5.167 


186 


13.638 


5.708 


91 


9-539 


4 


498 


139 


XI. 789 


5 


180 


187 


13.674 


5.718 


92 


9-592 


4 


514 


140 


11.832 


5 


192 


188 


13.711 


5.728 


93 


9.644 


4 


531 


141 


11.874 


5 


204 


189 


13.747 


5-738 


94 


9-695 


4 


547 


142 


11 .916 


5 


217 


igo 


13.784 


5.748 


95 


9-747 


4. 


563 


143 


11.958 


5 


229 


191 


13.820 


5.758 


96 


9.798 


4 


579 


144 


12. 


5 


241 


192 


13.856 


5.769 


97 


9.849 


4 


595 


145 


12.041 


5 


253 


193 


13.892 


5.779 


98 


9.899 


4 


610 


146 


12.083 


5 


265 


194 


13.928 


5.788 


99 


9-950 


4 


626 


147 


12. 124 


5 


277 


195 


13.964 


5-798 


100 


10. 


4- 


641 


148 


12.165 


5 


289 


196 


14. 


5.808 


101 


10.049 


4 


657 


149 


12 . 206 


5 


3oi 


197 


14-035 


5-818 


102 


10.099 


4- 


672 


150 


12.247 


5 


313 


198 


14.071 


5.828 


103 


10.148 


4- 


687 


151 


12.288 


5 


325 


200 


14.142 


5.848 


104 


10.198 


4 


702 


152 


12.328 


5 


335 


202 


14.212 


5.867 


105 


10.246 


4 


717 


153 


12.369 


5 


348 


204 


14.282 


5.886 


106 


10.295 


4 


732 


154 


1 2 . 409 


5- 


360 


206 


14.352 


5-905 


107 


10.344 


4 


747 


155 


12.449 


5 


371 


208 


14.422 


5.924 


108 


10.392 


4 


762 


156 


12.490 


5 


383 


210 


14.491 


5-943 


109 


10.440 


4 


776 


157 


12.529 


5 


394 


212 


14.560 


5.962 


110 


10.488 


4 


791 


158 


12.569 


5 


406 


214 


14.628 


5.981 


III 


10.535 


4 


805 


159 


12.609 


5 


417 


216 


14.696 


6. 


112 


10.583 


4 


820 


160 


12.649 


5 


428 


218 


14-764 


6.018 


"3 


10.630 


4 


834 


161 


12.688 


5 


440 


220 


14.832 


6.036 


114 


10.677 


4 


848 


162 


12.727 


5 


451 


222 


14.899 


6.05s 


"5 


10.723 


4 


862 


163 


12.767 


5 


462 


224 


14.966 


6.073 


116 


10.770 


4 


877 


164 


12.806 


5 


473 


225 


15- 


6.082 


117 


10.816 


4 


890 


165 


12.845 


5 


484 


226 


15.033 


6.091 


118 


10.862 


4 


904 


166 


12.884 


5 


495 


228 


15.099 


6.109 


119 


10 . 908 


4 


918 


167 


12.922 


5 


506 


230 


15.165 


6.126 


120 


10.954 


4 


632 


168 


12.961 


5 


517 


232 


15.231 


6.144 


121 


11. 


4 


946 


169 


13. 


5 


528 


234 


15.297 


6.162 


122 


11.045 


4 


959 


170 


13-038 


5 


539 


236 


15.362 


6.179 


123 


11.090 


4 


973 


171 


13.076 


5 


550 


238 


15.^27 


6.197 


124 


II. 135 


4 


986 


172 


13.114 


5 


561 


240 


15.^91 


6.214 


125 


11.180 


5 




173 


13-152 


5 


572 


242 


15.556 


6.231 


126 


11.224 


5 


013 


174 


13.190 


5 


582 


244 


15.620 


6.248 


127 


11.269 


5 


026 


175 


13.228 


5 


593 


246 


15-684 


6.265 


128 


11-313 


• 5 


039 


176 


13.266 


5 


604 


248 


15.748 


6.282 


129 


11-357 


5 


052 


177 


13-304 


5 


.614 


250 


15.811 


6.299 


130 


11. 401 


5 


065 


178 


13-341 


5 


625 


252 


15.874 


6.316 


131 


11-455 


5 


078 


179 


13-379 


5 


635 


254 


15.937 


6.333 


132 


11.489 


5 


091 


180 


13.416 


5 


646 


256 


16. 


6-349 


133 


11.532 


5 


104 


181 


13.453 


5 


.656 


258 


16.062 


6.366 


134 


11.575 


5 


117 


182 


13-490 


5 


667 


260 


16.124 


6.382 


135 


11.618 


5 


129 


183 


13-527 


5 


677 


262 


16.186 


6.398 


136 


11.661 


5 


142 


184 


13-564 


5 


687 


264 


16.248 


6.415 


137 


11.704 


5 


155 


185 


13.601 


5 


.698 


266 


16.309 


6.431 



I09 



Table of Square and Cube Roots.-- 


Continued, 


No. 


Square 


) 
Cube 


No. 


Square 


Cube 


No. 


Square 


Cube 


Root. 


Root. 


Root. 


Root. 


Root. 


Root. 


268 


16.370 


6.447 


360 


18.973 


7-113 


500 


22.360 


7-937 


270 


16.431 


6.463 


361 


19- 


7.120 


505 


22.472 


7 


963 


272 


16.492 


6-479 


362 


19.026 


7.126 


510 


22.583 


7 


989 


274 


16.552 


6.495 


364 


19.078 


7.140 


515 


22.693 


8 


oic; 


276 


16.613 


6.510 


366 


19.131 


7-153 


520 


22.803 


8 


041 


278 


16.678 


6.526 


368 


19.183 


7.166 


525 


22.912 


8 


067 


280 


16.733 


6.542 


370 


19-235 


7.179 


530 


23.021 


8 


092 


282 


16.792 


6-557 


372 


19.287 


7.191 


535 


23.130 


8 


118 


284 


16.852 


6-573 


374 


19-339 


7.204 


540 


23-237 


8 


143 


286 


16.91T 


6.588 


376 


19.390 


7.217 


545 


23-345 


8 


168 


288 


16.970 


6.603 


378 


19.442 


7.230 


550 


23-452 


8 


193 


289 


17- 


6.610 


380 


19-493 


7-241 


555 


23-558 


8 


217 


290 


17.029 


6.619 


382 


19-544 


7.225 


560 


23.664 


8 


242 


292 


17.088 


6.634 


384 


19-595 


7.268 


S65 


23.769 


8 


267 


294 


17.146 


6.649 


386 


19.646 


7.281 


570 


23-874 


8 


291 


296 


17.204 


6.664 


388 


19-697 


7.293 


575 


23-979 


8 


315 


298 


17.262 


6.679 


390 


19.748 


7.306 


580 


'H.083 


8 


339 


300 


17.320 


6.694 


392 


19.798 


7-318 


585 


24.186 


8 


363 


302 


17.378 


6.709 


394 


19.845 


7-331 


590 


24.289 


8 


387 


304 


17-435 


6.72:? 


396 


19.899 


7-343 


595 


24.392 


8. 


410 


306 


17.492 


6.738 


398 


19.949 


^•355 


600 


24.494 


8 


434 


308 


17-549 


6.753 


400 


20. ( 


7.368 


605 


24.596 


8 


457 


310 


17.606 


(^.1(^1 


402 


20.049 


7-5S0 


610 


24.698 


8 


480 


312 


17.663 


6.782 


404 


20.099 


7.395 


615 


24-799 


8 


504 


314 


17.720 


6.796 


•406 


20.149 


7.404 


620 


24.809 


8 


527 


316 


17.776 


6. 811 


408 


20.199 


7.416 


625 


25. ^ 


8 


549 


318 


17.832 


6.825 


410 


20.248 


7.428 


630 


25.099 


8 


572 


320 


17-888 


6.839 


412 


20.297 


7-441 


635 


25.199 


8 


595 


322 


17.944 


6.854 


414 


20.346 


7-453 


640 


25.298 


8 


617 


324 


18. 


6.868 


416 


20.396 


7-465 


645 


25-396 


8 


.640 


326 


18.055 


6.882 


418 


20.445 


7.476 


650 


25-495 


8 


652 


328 


18.110 


6.896 


420 


20.493 


7.488 


655 


25-592 


8 


1^ 


330 


18.165 


6.910 


422 


20.542 


7-5 


660 


25.690 


8 


332 


18.220 


6.924 


425 


20.615 


7-518 


665 


25.787 


8 


.728 


334 


18.275 


6.938 


430 


20.736 


7-547 


670 


25.884 


8 


-750 


336 


18.330 


6.952 


435 


20.857 


7-57^ 


675 


25.980 


8 


.772 


338 


18.384 


6.965 


440 


20.976 


7-605 


680 


26.076 


8 


-793 


340 


18.439 


6.979 


445 


21 .095 


7.634 


685 


26. 172 


8 


.815 


342 


18.493 


6.993 


450 


21 .213 


7.663 


690 


26.267 


8 


836 


343 


18.520 


7. 


455 


21.330 


7-691 


695 


26.362 


8 


.857 


344 


18.547 


7.006 


460 


21.447 


7.719 


700 


26.457 


8 


879 


346 


18.601 


7.020 


465 


21.563 


7-747 


705 


26.551 


8 


900 


348 


18.654 


7-033 


470 


21.679 


7-774 


710 


26.645 


8 


921 


350 


18.708 


7.047 


475 


21.794 


7.802 


715 


26.739 


8 


942 


352 


18.761 


7.060 


480 


2i.go8 


7.829 


720 


26.832 


8 


962 


354 


18.814 


7.074 


485 


22.022 


7-856 


725 


26.925 


8 


983 


356 


18.867 


7.087 


490 


22.135 


7-883 


730 


270O18 


9 


004 


358 


18.920 


7.100 


495 


22.248 


7 910 


735 


27 110 





024 



no 



Table of Square and Cube Roots. — Continued. 



No. 


Square 


Cube 


No. 
820 


Square 


Cube 


No. 
900 


Square 


Cube 


Root, 


Root. 


Root. 


Root. 


Root. 


Root. 


740 


27.202 


9-045 


28.635 


9-359 


30. 


9.654 


745 


27.294 


9.065 


\^^ 


28.722 


9.37S 


905 


30.083 


9.672 


750 


27.3S6 ■ 


9.085 


830 


28.80Q 


9-397 


910 


30.166 


9.690 


755 


27.477 


9.105 


835 


28.896 


9.416 


^^^ 


30.248 


9.708 


760 


27.568 


9.125 


840 


28.982 


9-435 


920 


30-331 


9-725 


765 


27.658 


9-145 


845 


29.068 


9-454 


925 


30-413 


9-743 


770 


27.748 


9.165 


850 


29-154 


9.472 


930 


30.496 


9.761 


775 


27.838 


9.185 


855 


29.240 


9.491 


940 


30.659 


9.796 


780 


27.928 


9.205 


860 


29-325 


9-509 


950 


30.822 


9.830 


785 


28.017 


9.224 


865 


29.410 


9-528 


960 


30-983 


9.864 


790 


28.106 


9 244 


870 


29-495 


9-546 


970 


3^-144 


9.898 


795 


28.195 


9-263 


875 


29.580 


9-564 


980 


31-304 


9-932 


800 


28.284 


9.283 


880 


29.664 


9-582 


990 


31.464 


9.966 


805 


28.372 


9.302 • 


885 


29.748 


9.600 


1000 


31.623 


10. 


810 


28.460 


9.321 


890 


29.832 


9.619 


1 100 


33.166 


10.323 


815 


28.548 


9-340 


895 


29.916 


9-636 


1200 


34.641 


10.627 



HOW TO GEAR A LATHE FOR SCREW-CUTTING. 

There is a long screw upon every screw-cutting latbe, 
called the lead-screw. This lead-screw feeds the carriage of 
the lathe while cutting screws, and has a gear wheel placed 
upon its end which takes motion from another gear wheel 
attached on the end of the spindle. Each of these gear 
Wheels contain a different number of teeth, so that different 
threads may be cut. All threads are cut a certain number 
to the inch, from one to fifty or more. In order to gear your 
iathe properly to cut a certain number of threads to the 
inch, you will first multiply the number of threads to the 
inch you wish to cut by ^, or any other small number, and 
this will give you the proper gear to put on the lead-screw. 
Now, with the same number, 4, multiply the number of 
threads to the inch in the lead-screw, and this will give you 
the proper gear to put on the spindle. 

Example.— Yow wish to cut a screw with ten threads to the 
Inch. Multiply 10 by 4 and it will give you 40: put this gear 
on the lead-screw. The lead-screw on your lathe has 7 
threads to the inch; multiply 7 by 4, and you will have 28. 
Put this gear on your spindle, and your lathe is geared to 
cut 10 threads to the inch. 



iir 

The rule above is for those lathes which have not a stud 
grooved into the spindle. As this stud runs with but half 
the speed of the spindle, you must change the rule somewhat. 

First, multiply the number of threads to the inch you wish 
to cut, by 4 (or some other small number), and this will give 
you the proper gear to put on your lead-screw. Next multi- 
ply the number of threads to the inch on your lead-screw by 
the same number, and multiply this product by 2^ and this 
will give you the proper gear to go on your stud. 

Example. — Using same numbers — 10 tim. : 4 is 40. Put this 
gear on your lead-screw; 7 times 4 is 28, and 2 times 28 is 56^ 
put this gear on your stud, and your lathe is grooved io cut 
10 threads to the inch. 



KITCHEN AND TABLE WASTES. 

Good management, both on the farm and in the house- 
hold, demands that all sources of waste be guarded against 
and that all by-products be utilized to the best advantage > 
That the kitchen and table wastes are more important 
sources of loss than are generally realized is brought out 
quite strikingly by investigations made by the New Jersey 
authorities. 

It is calculated that there could be gathered annually 
from 20,000 people about 2,080 tons of garbage, with an 
analysis and value equal to good barnyard manure. By 
treating with suitable solv-ents and drying the residue there 
could be secured 388^ tons of fertilizer, worth $14.69 
per ton, and over 82 tons of grease, which sells for an aver- 
age of $70 wherever this system is in operation. By cre- 
mation there would result 83 1-5 tons of ashes, worth 
$28.53 pel' ton. 

The total population of the cities and towns of New 
Jersey is approximately 918,722 and the garbage of this 
number of people would amount to 95,516 tons per year, 
from which could be manufactured 17,848 tons tankage, 
worth $262,180, and 3,726 tons of grease, worth $260,800, 
a total of $522,980. 

Should all this garbage be thus manipulated, there 
would be an increase in the plant-food supply to the extent 
of 45 per cent, of the tonnage of complete fertilizers used 
in that state during one year, which could not help but 
diminish the cost of fertilizers to the agriculturist. 



THE THEORY OF THE STEAM ENGINE. 

For many years engineers cared nothing about the 
theory of the steam engine. They went on improving 
and developing it without any assistance from men of pure 
science. Indeed it may be said with truth that the greatest 
improvement ever effected, the introduction of the com- 
pound engine, was made in spite of the physicist, who always 
asserted that nothing in the way of economy of fuel was to 
be gained by having two cylinders instead of one. In like 
manner, the mathematical theorist was content to make cer- 
tain thermo-dynamic assumptions, and, reasoning from them, 
to construct a theory of the steam engine, without troubling 
his head to consider whether his theory was or was not con- 
sistent with practice. Within the last few years, however, 
the theorist and the engineer have come a good deal into 
contact, and the former begins at last to see that the theory 
of the steam engine is laid down by Rankine, Clausius, and 
other writers, must be deeply modified, if not entirely re- 
written, before it can be made to apply in practice We 
have recently shown what M. Hirn, who combines in himseh 
practical and theoretical knowledge in an unusual degree, 
has had to say concerning the received theory of the steam 
engine, and its utter inutility for practical purposes ; and 
papers recently read before the Institutions of Mechanical 
and Civil Engineers, and the discussions which followed 
them, have done something to convince mathematicians that 
they have a good deal to learn yet about the laws which 
determine the efficiency of a steam engine. It has always 
been the custom to class the steam engine with other heat 
engines. It is now known that nothing can be more errone- 
ous. The steam engine is a heat engine std geiieris, and to 
confound it with a hot-air engine, or any motor working 
with a non-condensible fluid, is a grave mistake. It is not 
too much to say that many engineers now understand the 
mathematical theory of the steam engine better than do 
men making thermo-dynamics a special study. But there 
remains a large number of engineers who do not as yet quite 
see their way out of certain things which puzzle them, or 
which they fail to understand. There are, indeed, phe- 
nomena attending tne use of steam which are not yet quite 
comprehended by any one, and we may be excused if we say 
nmething about one or two points which require elucidation. 
One of these is the mode of operation of the iteam 
^^wCet. It is a very crude statement that it does good be- 
cause it keeps the cylinder hot. It might keep the cylinder 



113 

hot, and yet be a source of loss rather than gain ; and, asd 
matter of fact, it is doubtful now if the application of steam 
jackets to all the cylinders of a compound engine is advisa- 
ble. It is well known, too, that circumstances may arise, 
under which the jacket is powerless for good. Thus, for 
example, the late Mr. Alfred Barrett, when manager of the 
Reading Iron Works, carried out a very interesting series of 
experiments with a horizontal engine, in order to test the 
value of the jacket. This engine had a single cylinder fitted 
with a very thin wrought -iron liner, between which and the 
cylinder was a jacket space. The jacket was very carefully 
drained, and could be used either with steam or air in it. 
Experiments were made on the brake with and without 
steam in the jacket. The result was a practically infinitesi* 
mal gain by using steam in the jacket. In one word, the 
loss by condensation was transferred from the cylinder t(? 
the jacket. On the other hand, it is well known that single 
cylinder condensing engines must be steam jacketed if they 
are to be fairly economical. Circumstances alter cases, and 
the circumstances which attend the use of the jackets ar2 
more complex than appears at first sight. 

In considering the nature of the work to be done, we 
must repeat a fundamental truth which we have been the first 
to enunciate. A steam engine can discharge no water from 
it which it did not receive as water, save the small quantity 
which results from loss by external radiation and conduction 
from the cylinder, and from the performance of work. At 
first sight, the proposition looks as though it were untrue. 
Its accuracy will, however, become clear when it is carefully 
considered. After the engine has been fully warmed up, the 
cycle of events is this: Steam is admitted to the cylinder from 
the boiler. A portion of this is condensed. It parts with 
its heat to the metal with which it is in contact. The piston 
makes its stroke, and the pressure falls. The water mixed 
with the steam is then too hot for the pressure. It boils and 
produces steam, raising the toe of the diagram in a way well 
understood and needing no explanation here. During the 
return stroke the pressure falls to its lowest point, and the 
water, being again too hot for the pressure, boils, and is con- 
verted into steam, which escapes to the atmosphere or con- 
denser without doing work, and is wastea, The metal of the 
cylinder, etc., falls to the same temperalure as the water. 
At the next stroke the entering steam finds cool metal to 
come into contact with, and is condensed, as we have said, 
and so orj\ But the quantity condensed during the steam 
stroke is precisely equal to that evanorated during the 



114 

exhaust stroke, and consequently no condensed steam can 
leave the engine as water. 

Let us suppose, for the sake of argument, however, that 
an engine using 20 lbs. of 100 lbs steam per horse per hour, 
discharges two pounds of water per horse per hour. As 
each of these brought, in round numbers, ]i/6^ thermal units 
into the engine, and takes away only 212 units, it is clear 
that each pound must leave behma it 973 units ; conse- 
quently the cylinder will be hotter at the end of each revolu- 
tion than it was at the beginning, and the process would 
go on until condensatic^ must entirely cease. It will be 
urged, however, that a steam jacket certainly does discharge 
water, and that in considerable quantity, which it did not re- 
ceive ; and, a? tols is apparently indisputable, we are here face 
to face with one of the puzzles to which we have referred. 
The facta however, is in no wise inconsistent with what is ad- 
vanced. If an engine with an unjacketed cylinder regularly 
receives water from the boiler, that engine will discharge 
precisely an equal weight of water. The liquid will pass 
away in suspension in t he exhaust steam The engine has 
no power whatever of converting it into steam. The case 
of a jacketed engine is different. Such an engine will evap- 
orate in the cylinder water received with the steam, but it 
can only do so at the expense of the steam contained in the 
jacket. For every i lb. of water boiled away in the cylinder 
I lb. of steam is condensed in the jacket ; and the corollary 
is that, if an engine were supplied with perfectly dry steam, 
there would be no steam condensed in the jacket, save that 
required to meet the loss due to radiation and the conver 
sion of heat into work. The effect of the jacket will be to 
boil a portion of the water during the close of the stroke 
and so to keep up the toe of the diagram, and so get more 
work out of the steam. If, however, the steam was deliv- 
ered wet to the engine, it is very doubtful if the jacket could 
be productive of much economy. The water would be con 
verted into steam during the exhaust stroke, and no equiva 
lent would be obtained for the steam lost in the jacket. 

In a good condensing engine about 3 lbs. of steam pe 
horse per hour are condensed in the jacket. The cylinde 
will use, say, 15 lbs. of steam, so the total consumption i 
18 lbs. per horse per hour. It is none the less a fact, al 
though it is not generally known, that the average Lancashir 
boiler sends about 8 per cent, of water in the form of in 
sensible priming 'Vith the steam. Now, 8 per cent, of i 
lbs. Is 1.44 lbs., so that in this way we have nearly one-hal 
the jacket condensation accounted for as just explained 



One horse-power represents 2,562 thermal units expended 
per hour, or, say, 2.6 lbs. of steam of 100 lbs. pressure con. 
densed to less than atmospheric pressure; and 1.44— • 
260=- 4.04 lbs. per horse per hour, as the necessary jacket 
condensation, if no water is to be found in the working 
cylinder at the end of each stroke. That this quantity is not 
condensed only proves that the -^.vater received from the 
boiler, or resulting from the perform:urice of work, is not all 
re-evaporated. 

Something still remains to be written about the true 
action of the steam jacket, but this we must reserve for the 
present. We have said enough, we think, to show that, as 
we have stated, the jacket has more to do than keep the 
cylinder hot. With jacketed engines, more than any other, 
it is essential that the steam should be dry. In the case of 
an. unjacketed engine, water supplied from the boiler will 
pass through the engine as water, and do little harm; but, if 
the engine is jacketed, then the whole or part of this water 
will be converted into steam, especially during the period of 
exhaust, when it Ccan do more good than if it were boiled 
away in a pot in the engine-room. This is the principal 
reason why such conflicting opinions are expressed concern- 
ing the value of jackets. That depends principally on the 
merits of the boiler. 

TREATMENT OF NEW BOILERS. 

No ne^v boiler should have pressure put upon it at once. 
Instead, it should be heated up slowly for the first day, and 
whether steam is wanted or not. Long before all the joints 
are niade, or the engine ready for steam, the boiler should 
be set and in working order. A slight fire should be 
made and the water warmed up to about blood heat only, 
and left to stand in that condition and cool off, and absolute 
pressure should proceed by very slow stages. Persons who 
set a boiler and then build a roaring fire under it, and get 
steam as soon as they can, need not be surprised to find a 
great many leaks developed; even if the boiler docs not actu- 
ally and visibly leak, an enormous strain is needlessly put 
upon it which cannot fail to injure it. Of all the forces en- 
gineers deal with, there are none more tremendous than ex« 
mansion and contraction. 



Ii6 

COMPARATIVE ECONOMY OF HIGH AND 
SLOW SPEED ENGINES. 

In nearly every case where a flour mill is built, it is 
intended to be a permanent investment. The very nature of 
the milling business makes it necessary that the plant shall 
be built and operated, not for one, two or three years, but 
for a long term of years. It is the ambition of every mill 
owner, when he builds a mill, to make it the foundation of a 
permanent business, and, if he is wise, he will build such a 
mill and select such machinery as will prove economical, not 
in first cost, but in the long run. In no part of the milling 
plant is this more important than in the power outfit of 
steam mills, and, as most of the mills now being built are 
steam mills, the comparative economy of different kinds of 
steam engines becomes an important subject for considera- 
tion. No matter whether the mill is large or small, unless 
it is so advantageously located as regards its supply of fuel 
that the cost is practically nothing, any wastefulness in the 
consumption of fuel creates a steady drain on the earning of 
the mill which will seriously affect the balance of the profit 
and loss account, and, where fuel is expensive, may result in 
transierring the balance to the wrong side of the account, 

In selecting a power plant, it is a mistake, frequently made, 
to consider the first cost of the plant as of the highest 
importance, and any saving in this direction as so much 
clear gain. Especially is this the case in flouring mills of 
small capacity, where the builder's capital is limited, and 
where the idea is to get as much mill for as little money as 
possible. In such case, any money borrowed from the 
power plant to put into the balance of the mill, is bor- 
rowed at a ruinously high rate of interest, and it is, more- 
over, borrowed without any chance of repayment, except 
by throwing out the cheap plant and substituting the 
higher priced and more economical one at great expense. 
In no way is the miller more often misled than by the 
claims of the builders of the high-speed automatic engines, 
where the name automatic is relied upon to cover a mul- 
titude of sins in the direction of low economy. In this 
connection, some facts from a paper by J. A. Powers are 
instructive: 

After carefully analyzing the problem and considering 
the requirements of the load to be driven in electric 
lighting stations, which are more favorable for the high 
speed engines than is the case in flouring-mill work, Mr. 
Powers reaches the conclusion as to the different styles of 



117 

engines in f!ie consumption of steam, as stated by engine 
builders : 

Steam per H. P . per hour. 

High speed engines 28 to 32 lbs . 

Corliss engines, non-condensing 24 to ?6 lbs. 

" " condensinp^ 20 to 21 lbs. 

" " compound condensing 15 to 16 lbs. 

With an evaporation of eight pounds of water per 
pound of coal, the coal consumption would be as follows : 

C^oal per H. P. per hour 

High speed engine ., 3.50 to 4 lbs. 

Corliss engines, non-condensing 3 to 3.25 lbs, 

" " condensing 2.50 to 2.62 lbs. 

" " compound condensing 1.87102 lbs. 

As the interest on the first cost of the steam plant should 
properly be charged against its economy, the following 
statement of comparative first cost is given: 

High speed engine $31 to $36 per H. P. 

Corliss engines, non-condensing 42 to 46 " 

" " condensing 43 to 48 " 

** *' compound condensing 52 to 57 ** 

The comparison of first cost and fuel saving is as follows : 

Coal. ^ 
Cost. Consumption. 

High speed engine 100 per cent. 100 per cent. 

Corliss engine, non-condensing.... 131 ** 62 " 

" ** condensing 136 ** 56 ** 

** " compound cond'g.. 163 ** 44 ** 

If the cost of coal is taken at $3 per ton and interest h 
figured at six per cent., which figures may be considered a 
fair average, the results, based on the foregoing figures, fcr 
a plant of 403 horse-power, will be as follows : 

Cost of Coal Saving in Coal 

per day. over High Speed. 

High speed engine $24.75 $ 

Corliss engine, non-condensing. . . 18. go 5.85 

" " condensing 15-24 9-5i 

" " com'd condensing 11.64 i3-ii 

Interest Loss in Interest 

per day. over High Sp eed. 

High speed engine $2.36 $ 

Corliss engine, non-condensing 3.08 .72 

" " condensing 3.15 .79 

" " com'd condensing. 3.75 1.39 

And the saving per day over the high speed engine h: 

Corliss engine, non-condensing » $ 5.13 

" " condensing 872 

" " compound condensing 11 72 

So far as the steam consumption is concerned, res alts in 
every-day work show that the comparison is made as favor- 



ii8 

able as possible for the high speed engine, for, while records 
of actual tests of Corliss engines show that the figures given 
are not understated, the average of high speed engines after 
running a short time is not nearly as low as thirty-two 
pounds per indicated horse power per hour. So far as the 
cost of the respective plants are concerned, we should be 
inclined, especially for small plants, to put the average cost 
of the high speed plant a little lower than that, of the Corliss a 
little higher, but this change would not materially affect the 
result so far as comparative economy is concerned 

To bring the matter in shape to fairly apply to the 
requirements of the average lOO barrel mill, it may be assumed 
that the power required will be 50 horse power. In the 
absence of exact data as to the cost of the high speed plant, 
and to give it as favorable a showing as possible, the cost of 
the respective plants may bfe stated as follows : 

High speed $1,500 

Corliss, non-condensing 2,700 

" condensing 3,200 

'* compound condensing 4,300 

The economy, would then be : 

Water per 
H. P. per hour. H. 

High speed 32 lbs. 

Corliss non-condensing 26 lbs. 

" condensing 20 lbs. 

** compound condensing 16 lbs. 

And with coal and rate of interest assumed as above, 
based on a continuous run of 280 days, 24 hours per day, the 
comparison is summarized as follows : 

Cost of 
Fuel per Year 

High speed $2,016 

C^orliss, non-condensing 1,638 

** condensing 1,260 

" comp'd condensing 1,008 

The ratio of saving to difference in cost between the high 
speed plant and the others, may be stated as follows : 

Between high speed and Corliss non-conden :ng, 25 percent. 

** *' ** condensing 38^ " 

" ** ** comp.condens'g 30 " 

Or, in other words, it would take four years to save the 
difference in cost using the non-condensing Corliss, a little 
over two and one-half years if condensing, and three and one- 
half years if compound condensing. In either case, the sav- 
ing would be steadily continued, long after the cost of the 
plant had been wiped out. 



Coal per 


P. per hour. 


4 lbs. 


3-25 lbs. 


2.5 lbs. 


2. lbs. 



nterest. 
$ 90 
162 


Total. 

$2,106 

i,8co 


192 
258 


1,452 
1,266 



119 

RULE FOR SAFETY VALVE WEIGHTS. 

There seemt: to be a steady demand for this rule. The 
following is an easily remembered formula which may be of 
service to some : 

D2 X .7854 X P— D W + F 

' L ==^^- 

Now, this looks somewha^t formidable to those who are 
not familiar with calculations in any form, but a few words 
and a little study will make it clear to most persons. The 
explanation is this : 



D^ means that the diameter of the valve is to be mult 



plied by the same figure. If the valve is 4" diameter multi- 
ply it by 4. If it is 2" multiply it by 2; if 3/^" multiply it 
^y 3)4' This is called squaring the diameter. Now multi- 
ply the sum by .7854 and observe the decimal. This gives 
the area, as it is called, or number of square inches in the 
valve exposed to pressure. Of course, the end of the valve 
exposed to steam has been measured — not the top of it. 
Now multiply the sum last found by the pressure to be car- 
ried on the boiler, say 60, if it is 60 pounds. This gives the 
force pressing on the bottom of the valve to blow it off its 
seat. Take half the w^eight of the lever and whole weight 
of valve and stem from this last sum, and then multiply by 
the distance from the center of the valve-stem to the center 
of the hole in the short end of the lever. Divide the sum so 
found by the whole length of the lever. Then you have the 
weight of the ball to go on the end to give 60 lbs. per square 
inch on the boiler. 

This is, in brief, the rule ; but it is of no earthly use to thc?se 
who are not familiar with ordinary arithmetic, for they will 
be very likely to make serious errors in the result by mis- 
takes in figuring. 

The steamboat inspection law demands that candidates 
for marine licenses shall know this rule; but in many casr?s it 
would be just as useful to demand that a man should be able 
to jump twenty-five feet from a standstill, for those who are 
incompetent can learn the rule as above given, and pass mus- 
ter, without being practical working engineers, while those 
who have mathematical abilities and practical experience 
also, are only affronted by such appeals to the knowledge 
they have of their calling. 

The qualifications and abilities of engineers for their 
positions are in nowise determined by such trifling exercises 
as these. 



120 



Amount of horse power transmitted by single bolts to puU I 
leys running loo revolutions per miaute when the diameter oi 
the driving pulley is equal to the diameter of the driven pulley. 



Diameter 
of 
Pulley. 



Width of Belt in Inches. 



la. 

S 
9 



II 

12 

J3 

f& 

20 
21 
22 

23 

24 

26 
27 
28 
29 

30 
31 
32 
33 

34 
35 



H.P. 

•44 
.47 
.51 
•55 
.58 
.62 
.65 
.69 

•73 
.8 

.87 

'95 
1.02 
1.09 
1.16 
1.2^ 

I-3I 
1-39 
1.45 
1.52 

1.6 
1.67 

3-8 

3-9 
4.1 
4.2 
4.4 

4-5 

4.7 

4.8 

4.9 
5.1 



H. P. 

•54 

59 

.64 

-68 

-n 
'11 
.82 

.86 
.91 
I. 

1.09 
1. 18 
1.27 
1.3.6 
1.45 
1.55 
1.64 

1.82 
1. 91 
2. 

2.09 

4.4 

4.5 

4.7 

4.9 

51 

5-3 

6.2 
6.4 



3 


3>^ 


4 


4/2 


5 


6 


HP 


H. P. 


H.P. 


H.P. 


H.P. 


H.P 


.65 


.76 


•87 


.98 


1.09 


1.31 


•71 


•f^ 


.95 


1.07 


1. 19 


1.42 


.76 


.89 


I.OI 


1. 14 


1.27 


'•53 


.82 


•95 


1.09 


'•23 


r.36 


1.64 


.87 


1.02 


m6 


1-31 


1.45 


1.75 


•93 


1.08 


I 2\ 


1.39 


1-55 


1.86 


98 


1. 15 


' 3J 


1.48 


1.64 


1.97 


1^4 


1. 21 


1.39 


1.56 


1.74 


2.0^ 


1.09 


1.27 


1.45 


1.63 


1. 81 


2.18 


1.2 


1.4 


1.6 


1.8 


2. 


:2,62 


1.31 


1-53 


1-75 


'•97 


2.18 


1.42 


1.65 


1.89 


2.12 


2.36 


2.83 


1.52 


1-77 


2.02 


2.27 


2.53 


•3-<>5 


1.64 


1.91 


2.19 


2.46 


2.73 


3.29 


J. 74 


2.03 


2.32 


2.61 


291 


3-4^ 


1,85 


2.16 


2.47 


2.78 


309 


Z'l^ 


r.96 


2.29 


2.62 


2.95 


3-27 


392 


2.07 


2.42 


2.76 


^u 


3-45 


4.14 


2.18 


2.^5 


2.91 


3-27 


3-64 


4-36 


2.2Q 


2.67 


3-05 


3-44 


6-82 


4.58 


2.4 


2.8 


3-2 


3.6 


4 


4.8 


2.5» 


2.93 


3-35 


3-75 


4.18 


5.02 


5-2 


7- 


8.7 


10.5 


12.2 


14- 


5.5 


7-3 


9.1 


10.9 


12.7 


I4S 


5-7 


7.6 


9-5 


''•3 


13-2 


15. r 


5.9 


7.8 


9.8 


11.8 


n-i 


15.6 


6.1 


8.1 


10.2 


12.2 


14-3 


16.3 


6.3 
6.6 


8.4 


10.5 


12.6 


14.8 


16.9 


•8.7 


10.9 


13- 1 


15.3 


17.4 


6.8 


9- 


"•3 


135 


15.8 


la 


7. 


H 


II. 6 


14 


16.3 


18.6 


7.2 


9.6 


12. 


14.4 


16.8 


19.2 


H 


9-9 


12.4 


14.8 


17-3 


19.8 


7.6 


10,2 


12.7 


153 


17-9 


20.4 



I2i 



Amount of horse power transmitted by smgle belts to pul- 
leys running ICX) revolutions per minute when the diameter ol 
the driving wheel is equal to the diameter of the driven puUey. 



Diameter 

of 




Width of Belt 


• IN Inches. 




Pulley. 


2 


2/2 


3 


?>% 


4 


A'A 


5 


6 


In. 


H.P. 


H. P. 


H. P. 


H. P. 


H. P. 


H.P. 


H. P. 


H.P. 


36 


5-2 


6.5 


7.8 


10.5 


13- 1 


'5-^ 


18.3 


20.9 


37 


5.4 


6.7 


8.1 


10.8 


13.5 


16.2 


18.9 


21.5 


38 


5-5 


6.9 


l'^ 


II. 


13.8 


16.6 


19.3 


22.1 


39 


S'1 


7.1 


8.5 


II-3 


14.2 


17- 


19.9 


22.7 


40 


5.8 


7.3 


%.7 


11.6 


14.6 


17.5 


20.4 


23.3 


42 


6.1 


7.6 


9.2 


12.2 


^1*3 


I8.2 


21.4 


24.3 


44 


6.4 


8. 


9.6 


12.8 


16. 


19.2 


22.4 


25.6 


46 


6.7 


8.4 


10. 


13-4 


16. 


20.1 


23.4 


26.8 


48 


7. 


8.8 


10.4 


14. 


17.4 


21. 


24.4 


28. 


50 


7.2 


9- 


10.9 


14.6 


18.2 


21.8 


25.4 


29. 


54 


7.8 


9.8 


11.8 


15-6 


19.6 


2^.6 


26.4 


31.2 


60 


8.8 


10.8 


13-1 


17.4 


21.8 


26.2 


30.6 


34.8 


66 


9.6 


12. 


14.4 


19.2 


24. 


28.8 


33.6 


384 


72 


10.4 


13- 


15.6 


21. 


26.2 


3'-i 


z(>^(> 


41.8 


78 


11.4 


14.2 


17. 


22.6 


28.4 


34- f 


30.8 


^^i 


84 


12.2 


15.2 


19.4 


24.4 


30.6 


36.4 


42.8 


48.6 


26 


3-8 


4-7 


57 


7-? 


9-5 


11-3 


13.2 


I5-J 


27 


3-9 


4.9 


5.9 


7.8 


9.8 


11.8 


^2>'7 


156 


28 


4.1 


5-1 


6.1 


8.1 


10.2 


12.2 


14.3 


16.3 


29 


4.2 


5-3 


^A 


8.4 


10.5 


12.6 


14.8 


16.9 


30 


4.4 


5-4 


6.6 


8.7 


10.9 


13- 1 


15.3 


17.4 


31 


4-5 


5-6 


6.8 


9- 


II-3 


13-5 


15.8 


18. 


32 


4-7 


5.S 


7. 


9-3 


II. 6 


14. 


16.3 


18.6 


33 


4.8 


6. 


7.2 


9.6 


12. 


14.4 


16.8 


19.2 


34 


4.9 


6.2 


7.4 


9.9 


12.4 


14.8 


17-3 


19.8 


35 


5-1 


6.4 


7.6 


10.2 


12.7 


153 


17.9 


20.4 


36 


5-2 


6.5 


7.8 


10.5 


131 


15.7 


18.3 


20.9 


37 


5.4 


6.7 


8.1 


10.8 


135 


16.2 


18.9 


21-5 


38 


5-5 


6.9 


l'^ 


II. 


13.8 


i66 


19.3 


22.1 


39 


5-7 


7.1 


8.5 


II. 3 


14.2 


17. 


19.9 


22.7 


40 


5-^ 


7.3 


^'7 


II. 6 


14.6 


17.5 


20.4 


23-3 


42 


6.1 


7.6 


9.2 


12.2 


15-3 


18.2 


21.4 


25.? 


44 


6.4 


8. 


9.6 


12.8 


16. 


19.2 


22.4 



HOW TO TRUE AN EMERY WHEEL. 
A P. e'Tiery wheel may be trued by ^asing a bar of rough iroD 
-yr ( opper as a turning tool. , 



122 

HOW TO FIND THE DIAMETER OF HIGH AND 

LOW PRESSURE CYLINDERS AT DIF- 

FERENT PRESSURES. 

The following is a table from actual practice giving the 
diameters of the high and low pressure cylinders at different 
boiler pressures, the piston speed being taken at 420 ft. 
minute : 



r^ 


^ . 


Boiler pres- 


Boiler pres- 


Boiler pres- 


la. 




sure 45 lbs. 


sure 80 lbs. 


:sure 125 lbs. 




1^ 


Diam. H.P. 


Diam. H.P. 


Diam. H.P. 




5^ 


cyHnder. 


cylinder. 


cylinder. 


10 


7Xin. 


4 in. 


SVs in. 


3X in- 


20 


10 


5^ 


5- 


A'A 


25 


iiK 


6j^ 


5K 


5/s 


30 


I2>/8 


7>^ 


6X 


S% 


40. 


hX 


8X 


7/8 


6^8 


50 


16 


9X 


8 


7^^ 


100 


22>^ 


13 


iiX 


loYi 


150 


27^ 


16 


14 


12^8 



ANIMAL POWER. 

Average power of a man working to the best advantage 
is lifting 70 lbs. I ft. in i second for 10 hours per day, or 
4,200 fr. lbs. per minute, =0.127 horse-power. 

The average work of a horse in a day of 8 hours is 
22,500 lbs. raised I ft. in I minute, or 0.68 of the theoreti- 
cal horse-power. 

A horse can only exert a theoretical horse -power for 6 
hours per day. 

I indicated horse-power =1.4 times the average power 
of a horse. 

The strength of a horse is equivalent to that of 6 men. 

HOW TO MAKE A STRONG FLANGE JOINT. 

To make a flange joint that won't leak or burn out on 
steam pipes, mix two parts white lead to one part red lead to 
a stiff Toutty ; spread on the flange evenly, and cut a liner of 
gauze wire — like mosquito net wire — and lay on the putty, of 
course cutting out the proper holes ; then bring the flanges 
*«fair," put in the bolts and turn the nuts on evenly. For a 
permanent joint this is A i. 



123 

DENSITY OF WATER. 



Tempera- 
ture F. 


Comparative 

Volume. 

Water 32"-=!. 


Comparative 

Density. 
Water 32^=1. 


Weight of 
I Cubic Foot. 


32 


I .00000 


I. 00000 


62.418 


35 


0.99993 


1.00007 


62.422 


40 


0.99989 


I. 0001 I 


62.425 


45 


0.99993 


1.00007 


62.422 


46 


I. 00000 


I .00000 


62.418 


50 


I. 00015 


.99985 


62.409 


55 


1.00038 


.99961 


62.394 


60 


1.00074 


.99926 


62.372 


65 


I.00119 


.99881 


62.344 


70 


I. 00160 


.99832 


62.313 


75 


1.00239 


.99771 


62.275 


80 


1.00299 


.99702 


62.232 


85 


1.00379 


.99622 


62.182 


90 


1.00459 


.99543 


62.133 


95 


1.00554 


.99449 


62.074 


ICX) 


1.00639 


-99365 


62.022 


105 


1.00739 


.99260 


61.960 


no 


1.00889 


.99119 


61.868 


115 


1.00989 


.99021 


61.807 


120 


1.01139 


.98874 


61.715 


125 


I. 01 239 


.98808 


61.654 


130 


I. 01 390 


.98630 


61.563 


135 


I. 01539 


.98484 


61.472 


140 


1.01690 


•98339 


61.381 


145 


1-01839 


.98194 


6l;29I 


150 


1.01989 


.98050 


61.201 


155 


I. 02 164 


.97882 


61.096 


160 


1.02340 


.97715 


60.941 


165 


1.02589 


.97477 


60.843 


170 


J . 02690 


.97380 


60 783 


175 


1.02906 


.97193 


60.665 


i8o 


I. 03 100 


.97006 


60.543 


185 


1.03300 


.96828 


60.430 


190 


I .03500 


.86632 


60.314 


195 


1.03700 


.96440 


60. 198 


2CX) 


I .03889 


.96256 


6o.o8r 


205 


I. 0414 


.9602 


59.937 


210 


I .0434 


.9584 


59 822 


"12 


1.0444 


.9575 


59.769 



i24 



CALKING STEAM BOILERS. 

No well-made boiler ought to require to be heavily calked, 
and to provide for light calking it is imperative that the 
plates of a boiler should be effectually and thoroughly 
cleaned of all fire scale before being riveted up. Good boiler 
vi^ork should be very nearly tight without calking, but it is 
difficult to attain this degree of excellence with hand work. 
Hydraulic riveting, in which the plates are forcibly pressed 
together before the rivet is closed and made to fit the hole, 
will, if carefully doue, be found to give a tight boiler without 
calking. It is obvious that tightness can only be secured by 
insuring metallic contact. If all the rivets fill the holes per- 
fectly, no leakage can percolate past the rivet heads. If any 
rivet heads require calking, they should be cut out and a 
fresh rivet inserted, as a leak is a sure indication that the 
rivet does not fill the hole, and is possibly imperfectly closed 
in addition. It is also obvious that to insure a tight boiler 
the surfaces of the plates must be in metallic contact, and 
must remain so when the boiler is subjected to the working 
pressure which, with the alterations of temperature, will pro- 
duce certain inevitable changes in the form of the boiler. It 

is obviously necessary 
that the surfaces of the 
plates should be smooth 
in order to insure metal- 
lic contact, and that 
this cannot be attained 
unless the scale covers 
the plates completely, 
or is wholly detached. 
As a slight pin-hole in 
the magnetic oxide with 
which steel plates are 
coated will cause aleak- 
age, and under certain 
circumstances, set i^ a 
galvanic and corrosive 
action, it is advisable to 
easily done with irori 




Fig. I. 




Fig. 2. 



wholly detach the scale. This is 

plates, but steel plates cannot be completely cleaned of mag- 
netic oxide by the usual mechanical methods. An excellent 
and effective method is that used at the Crewe Works of the 
London & Northwestern Railway (England). The plates 
are brushed over with muriatic acid diluted with water, and 
applied with a brush or pad made with woolen waste- This 



125 

loosens and detaches all the scale, and the plates rae then 
cleaned by a solution of lime, which effectually removes any 
surplus muriatic acid. If the plates are not wanted imme- 
diately, they can be protected from rust by a coat of turpen- 
, tine and oil. If these precautions be not taken, the scale or 
idirt upon the plates becomes crushed to powder by the 
squeeze of the riveter, and a close metal to metal joint is i en- 
dered impossible, and the consequent leakage must be stopped 
by calking. With clean plates much calking is not neces- 
sary, nor should it be countenanced, for, after all, calking is 
only an evidence of, and a concession to, more or less in- 
ferior, or, at least, imperfect workmanship. 

Some boiler-makers firmly believe that calking should be 
performed both internally and externally, and we may fre- 
quently hear this double calking expatiated upon as adding 
to the value of a boiler. As a matter of fact, however, in- 
ternal calking should never be resorted to. By internal calk- 
ing we mean specially to indicate the calking of edges ex- 
posed to steam or water, especially the latter, for long expe- 
rience has shown, with very little room for doubt, that internal 
calking has frequently been either a cause or an aid m the 
initiation of corrosive channeling of the plates along the line 
of the rivet seams. Though channeling is commonly met 
with along the longitudinal seams, being started, more fre- 
quently than by any other cause, by the want of perfect cir- 
cularity of the boiler, yet it is aggravated by the calking of 
the edge of the plate which borders the channeling, and the 
explanation is that an abnormal stress is set up in the plate 
upon which the calked edge is forced down, and too fre- 
quently the calking tool itself is driven so severely upon the 
plate surface as to cause an injury which develops as chan- 
neling when other conditions, such as bad water, etc., are 
present. These causes have been mainly coiitributory to the 
modern practice of outside calking only, and, with proper 
workmanship, this is all that should be required, but the best 
practice rejects any calking at all in the strict acceptation of 
the term, and demands that the edges of the plates shall be 
planed and "fullered;" fullering being the thickening up of 
the whole edge of the plate by means of a tool having a face 
equal to the plate thickness. With such a tool as this, it is 
impossible to wedge apart the plates forming the joint, and 
so frequently done in the manner shown (exaggerated) in 
Fig.%, when the narrow edge of the calking tool, driven per- 
haps by a heavy hammer, actually forces the plates apart and 
insures a tight joint only by the piece of damaged plate corner 
which remains driven fast into the gap. 



1,J^ 

In contrast io this. Fig. 2 may he taken to fairl> I'epre' 
Bent the correct action of the more con*ect fullering tool, the 
plate edge being simply thickened, and contact between the 
two plates rendered certain for some distance in from the 
edge. To thus thicken, or " fuller " a plate, requires con- 
siderable power, and yet, even the use of a more than usually 
heavy hammer will not cause injury, as it certainly would do 
in careless hands, if used with a narrow calking tool. All 
modern first-class boiler work in Eng^land is inviarabiy ful- 
lered, and, though the practice of inside calking is still fol- 
lowed by firms who " fuller, " nevertheless, outside work is 
gaining the day. A further advantage of the " fulling " tool 
may be named. If inside calking be still practiced, the 
tendency to cause grooving will be less marked than with 
the narrow tool, and where, as at times, it is absolutely 
necessary to internally calk, as may sometimes happen, the 
iast is a great point in favor of the broad tool. 

The foregoing remarks are suggested by a few notes on 
calking in an engineering work, wherein calking tools are 
described as having from }i to 3-16 of thickness, and "best 
work" as being calked both inside and out. In itself, 
calking properly carried out, and lightly performed on good, 
close-riveted joints, is not necessarily bad, but too frequently 
is badly performed by careless workmen and boys, and hence 
** fullering," which is better practice, and is also a safeguard 
against carelessness, is to b'^^ preferred to the old method. 

HOW TO THAW OUT A FROZEN STEAM-PIPE. 
A good way to thaw out a frozen-up steam pipe, is to 
take some old cloth, discarded clothes, waste, old carpet, or 
anything of that kind, and lay on the pipe to be thawed ; 
then get some good hot water and pour it on. The cloth 
will hold the heat on the pipe, and thaw it out in five min- 
utes. This holds good in any kind of a freeze, water- wheel, 
or anything else. 

How many people, outside of practical men, know that 
steam is an invisible gas until the moisture it bears is con- 
densed by contact with cold air. Such is a fact, neverthe- 
less, as we may readily see by boiling vvater in a glass vessel. 
The bubbles that rise to the surface of the water are appar- 
ently empty — the white vapor appears after they burs c in the 
air at the surface of the water. 



127 

THE PREVENTION OF ACCIDENTS FROM RUN. 
NING MACHINERY. 

A German commission was appointed to investigate acci« 
dents in mills and factories, and draw up a series of rules fot 
their prevention. Some of these rules are as follows: 

SHAFTING. 

All work on transmissions, especially the cleaning and 
lubricating of shafts, bearings and pulleys, as well as the 
binding, lacing, shipping and unshipping of belts, must be 
performed only by men especially mstructed in, or charged 
with, such labors. Females and boys are not permitted to 
do this work. 

The lacing, binding or packing of belts, if they lie upon 
either shaft or pulleys during the operation, must be strictly 
prohibited. During the lacing and connecting of belts, 
strict attention is to be paid to their removal from revolv- 
ing parts, either by hanging them upon a hook fastened to 
the ceiling, or in any other practical manner; the same 
applies to smaller belts, which are occasionally unshipped 
and run idle. 

While the shafts are in motion, they are to be lubricated, 
or the lubricating devices examined only when observing the 
following rules: a. The person performing this labor must 
either do it while standing upon the floor, or by the use of b. 
Firmly located stands or steps, especially constructed for the 
purpose, so as to afford a good and substantial footing to the 
workman, c. Firmly constructed sliding ladders, running 
on bars. d. Sufficiently high and strong ladders, especially 
constructed for this purpose, which, by appropriate safe- 
guards (hooks above or iron points below), afford security 
against slipping. 

The cleaning and dusting of shafts, as well as of belt or 
rope pulleys mounted upon them, is to be performed only 
when they are in motion, either while the workman is 
standing : a, on the floor ; or <5, on a substantially con- 
structed stage or steps ; in either case, moreover, only by 
the use of suitable cleaning implements (duster, brush, etc.), 
provided with a handle of suitable length. The cleaning of 
shaft bearings, which can be done either while standing upon 
the floor or by the use of the safeguards mentioned above, 
must be done only by the use of long-handled implements. 
The cleaning of the shafts, while in motion, with cleaning 
waste or rags held in the hand, is to be strictly prohibited., 

All shaft -bearings are to be provided with automatic 
lubricating apparatus. 



128 

Only after the engineer has given the well understood 
signal, plainly audible in the work-rooms, is the motive en- 
gine to be started. A similar signal shall also be given to 
a certain number of work-rooms, if only their part of the 
machinery is to be set in motion. 

If any work other than the lubricating and cleaning of 
the shafting is to be performed while the motive engine is 
standing idle, the engineer is to be notified of it, and in what 
room or place such work is going on, and he must then allow 
the engine to remain idle until he has been informed by 
proper parties that the work is finished. 

Plainly visible and easily accessible alarm apparatus shall 
be located at proper places in the work-rooms, to be used in 
cases of accident to signal to the engineer to stop the 
motive engine at once. This alarm apparatus shall always 
be in working order, and of such a nature that a plainly 
audible and easily understood alarm can at once be sent to 
the enginef^r in charge. 

All projecting wedges, keys, set-screws, nuts, grooves, or 
other parts of machinery, having sharp edges, shall be sub- 
stantially covered. 

All bells and ropes which pass from the shafting of one 
story to that of another shall be guarded by fencing or 
casing of wood, sheet-iron or wire netting four feet six 
inches high. 

The belts passing from shafting in the story under- 
neath and actuating machinery in the room overhead, 
thereby passing through the ceiling, must be inclosed with 
proper casing or netting corresponding in height from the 
flooi to the construction of the machine. When the con- 
struction of the machine does not admit of the introduction 
of casing, then, at least, the opening in the floor through 
which the belt or rope passes should be inclosed with a 
low casing at least four inches high. 

Fix:jd shafts, as well as ordinary shafts, pulleys and fly- 
wheels, running at a little height above the floor, and being 
within the locality where work is performed, shall be securely 
covered. 

These rules and regulations, intended as preventions of 
accidents to workmen, are to be made known by being con- 
spicuously posted in all localities where labor is performed. 

ENGINEERS. 

The attendant of a motive engine is responsible for the 
preservation and cleaning of the engine, as well as the floor 
of the engine-room. The minute inspection and lubrication 



129 

of the several parts of the engine is to be done before it is 
set in motion. If any irregularities are observed during the 
performance of the engine, it is to be stopped at once, and 
the proper person informed of the reason. 

The tightening of wedges, keys, nuts, etc., of revolving 
or w^orking parts, is to be avoided as much as possible during 
the motion of the engine. 

When large motive engines are required to be turned 
over the dead point by manual labor, the steam supply valve 
is to be shut off. 

After stoppage, either for rest or other cause, the engine 
is to be started only after a well-understood and plainly 
audible signal has been given. The engineer must stop his 
engine at once upon receipt of an alarm signal. 

The engineer has the efficient illumination of the engine- 
room, and especially the parts moved by the engine, under his 
charge. 

The engineer must strictly forbid the entrance of unau 
thorized persons into the engine-room. 

An attendant of a steam or other power motor, who \a 
charged with the supervision of the engine as his only duty, 
is permitted to leave his post only after he has turned the 
care of the engine over to the person relieving him in the 
discharge of his duties. 

The engineer is charged with the proper preservation of 
his engine, and means therefor. He must at once inform 
his superior of any defect noticed by him. 

The engineer on duty is permitted only to wear closely 
fitting and buttoned garments. The wearing of aprons or 
neckties with loose, fluttering ends, is strictly prohibited. 

GEARING. 

Every work on gearing, such as cleaning and lubricating 
shafts, bearings, journals, pulleys and belts, as well as the 
tying, lacing and shipping of the latter, is to be performed 
only by persons either skilled in such work, or charged with 
doing it. Females and children are absolutely prohibited 
from doing such work. 

When lacing, binding or repairing the belts, they must 
either be taken down altogether from the revolving shaft or 
pulley, or be kept clear of them in an appropriate manner. 
Belts unshipped for other reasons are to be treated in the 
same manner. 

The lubricating of bearings and the inspection of luori- 
cating apparatus must, when the shafting is in motion, be 
performed either while standing upon the floor or by the use 



I30 

of steps or ladders, specially adapted for this purpose, or 
proper staging or sliding ladders. The lubrication of 
wheel work and the greasing ol belts and ropes with solid 
lubricants is absolutely prohibited during the motion of the 
parts. 

In case of accident, anyworkman is authorized to sound 
the alarm signal at once by the use of the apparatus 
located in the room for this purpose, to the engineer in 
charge. 

The following rules, classified under proper sub-heads, 
are published by the Technische Verein, at Augsburg: 

TO PREVENT ACCIDENT BY THE SHAFTING. 

While the shafts are in motion, it is strictly prohibited: 
a. To approach them with waste or rags, in order to clean 
them. b. In order to clean them, to raise above the floor 
by means of a ladder or other convenience. 

It is allowable to clean the shafting and pulleys only while 
in motion. 

These parts of the miachinery must be cleaned by means 
.vf a long-handled brush only, and while standing upon the 
floor. 

The workmen charged with these or other functions 
about the shafting must wear jackets with tight sleeves, and 
closely buttoned up ; they must wear neither aprons nor 
neckties with loose ends. 

Driving pulleys, couplings and bearings are to be cleaned 
only when at rest. 

This labor should, in general, be performed only after the 
close of the day's work. If performed during the time of 
an accidental idleness of the machinery, or during the time 
of rest, or in the morning before the commencement of 
work, the engineer in charge is to be informed. 

HOW TO FIND THE HORSE-POWER OF AN 
ENGINE. 

Multiply the square of the diameter of the cylinder by 
0.7854, and, if the cut-off is not known, multiply the product 
by four-fifths of the boiler pressure; multiply the last 
product by the speed of the piston in feet per minute (or 
twice the stroke in feet and decimals, multiplied by the revo- 
lutions per minute). Divide the final product by 33.<^oo. 
and the horse-power will be the answer. 



131 
ECONOMY IN THE USE OF AN INJECTOR. 

The following is an interesting discussion of the economy 
dae to the use of an injector, in comparison with a direct- 
acting steam-pump, both with and without a feed-water 
heater, and a geared pump with heater. Although the in- 
vestigation is theoretical, it seems to be based on reliable 
data, so that the results, as summarized in the following 
table, difter little, in all probability, from the figures which 
would be obtained by actual experiment : 







Temperature 


Relative amount 


Per cent, of 


M 


anner of feeding 


of feed- 


of coal required 


fuel saved 




boiler. 


water. 


for feed 


over first 






Fahrenheit. 


apparatus, in 
equal times. 


case. 


^. 


D ire c t- acting ) 










steam-pump, >• 


6o 


100 


0. 




no heater ) 








2. 


Injector, no heater 


1500 


98.5 


I . :; 


3- 


Injector, with { 
heater j" 


200 


93-8 


6.2 


4- 


D irec t- acting ) 










steam-Dump, V 


2000 


87.9 


12 ,1 




with heater. . . ) 








5- 


Ge a red-pump, 
actuated by 










the main en- } 


2000 


86.8 


13.3 




gi n e , with 
heater J 

















This does not make the comparison between the eco- 
nomical performance of an injector and pump actuated by 
the main engine, wi.hout heater in each case, or, in other 
words, he does not consider one of the most general divisions 
of the problem. Some experiments made on the Illinois 
Central Railroad may be briefly cited to supplement the dis- 
cussion. The figures given represent averages of eight trips 
of 128 miles in each case : 



Pounds of coal per trip. . . 
Pounds of water per trip. 
Pounds of water evapo- 
rated per pound of coal 



Feeding 

with 

pump. 

9.529 
48,888 

5-H 



Feeding 
with 
injector. 

8,736 
46,826 



Per cent, 
of grain 
for injector 
9.08 
4.04 



5.26 4.28 



In the experimei/ts with pump, the trains were slightly 
heavier than when the injector was used, and more time was 



132 

lost in switching and standing, for which reason the experi- 
menters considered that the economy of coal consumption 
/or the injector should he reduced from 9.08 to 6.21 per cent. 
Some incidental advantages were observed in the case of the 
injector, the boiler steamed more freely, and there was less 
variation of pressure. 

TELEPHONES. 

Telephones are of two kinds— magneto and electric. In one 
sense of the word they both work on the same principle, 
namely: A series of pulsations, corresponding in length and 




SECTION OF A BLAKE TRANSMITTER 

Strength to the sound waves made by the voice, cau-se simi- 
lar pulsations in the receiving end of the telephone circuit, 
and these pulsations in turn make sound waves which reach 
the ear. Magnetism and electricity work together in a tele- 
phone. If a wire is moved just in front of the poles of a 
magnet, whether it be an electro or a permanent magnet, a 
current of electricity is induced in the wireu If a current of 
electricity is set to flowing around a piece of soft iron, that 



533 

piece of iron becomes an electro-magnet aL:<l remains as such 

as long as ttie electricity flows around it. A steel magnet, 
however, is always a magnet unless particular pains are 
taken to de-magnetize it. Around every magnet is a mag- 
netic field, and the field is traversed by what are known as 
lines of force. Any change in the lines of force induce elec- 
tricity, and this is the bottom principle in the working part 
of a telephone. In the receiver of a telephone of the Bell pat^ 




SECTION OF A BELL RECEIVER. 

tern is a bar or straight permanent magnet. At one end of 
this bar-magnet is an electro-magnet. Two small copper 
wires lead back from the electro-magnet to the closed end of 
the receiver and the diaphragm of the telephone fits into the 
.case so near the poles of the electro-magnet as to almost 
touch it. This is a magneto-telephone, and such telephones 
are usually used as receivers. When the diaphragm Is 
moved back and forth by sound waves, it cuts the lines ol 
force in the magnetic field and induces undulatory currentF 



134 

of electricity, which are transmitted by the telephone wire 
to the other telephone. In practice, however, the tindulatory 
currents are induced by the transmitter which is an electric 
telephone. The most common type of transmitter in the 
United States is the Blake. In this transmitter the working 
parts are the diaphragm; touching it is a platinum bottom 
which in turn rests lightly against a carbon button. The 
current of electricity flows through the carbon button, then 
through the platinum bottom and so out to the wires. When 
the diagraphragm, vibrating on account of the sound waves 
of the voice, presses against the platinum bottom, it in turn 
presses against the carbon button giving it a succession of 
little squeezes which make the current of electricity stronger 
or weaker, thus producing an undulatory current. The un- 
dulations carried over the wires affect the magnet in the re- 
ceiving telephone, causing the diaphragm to respond, thus 
reproducing speech at that end of the telephone circuit. 

RAPID RAILWAY TRANSIT. 

As an illustration of the speed at which railway traveling 
can be effected wnen the necessity arises, it may be mentioned 
that an American having missed the train in London, and 
having to catch an Atlantic steamer at Liverpool, proceeded 
by the ordinary train to Crewe, where a special engine had 
been chartered to convey him direct to Liverpool. The dis- 
tance between Crewe and Liverpool is 36 miles, and one of 
the large Crewe engines completed the journey in 33 min- 
utes, reaching the landing stage at Liverpool 10 minutes 
before the timed departure of his steamer. 

USEFUL CEMENTS. 

A cement said to resist petroleum is made by taking three 
parts resin, one part caustiij soda to five of water, boiled to- 
gether, the resin being melted first, of course. This makes a 
resin soap, to which must be added half its weigh of plaster. 
It hardens in forty minutes. Useful for uniiing lamp tops 
to glass. Glycerine and litharge, mixed thoroughly, is said 
to form a cement which hardens rapidly, and will join iron 
to iron or iron to stone. Not affected by water or acids. 

A cement for leaky roofs is made by the following articles 



135 

in the proportions named: 4 pounds resin, i pint linseed oil, 
2 ounces red lead; stir in finest white sand until of the 
proper consistency, and apply hot. It possesses elasticity, 
and is fireproof. 

Starch and chloride of zinc form a cement which hardens 
quickly, and is durable. Sometimes used for stopping blow- 
holes in castings. 

A cement for uniting metal to glass is made with 2 ounces 
thick solution of glue, i ounce linseed oil varnish. Stir and 
boil thoroughly. The pieces should be tied togeth'^" for 
three days. 

A cement of 100 parts each white sand, litharge ..nd 
liniestone, combined with 7 parts of linseed oil, makes the 
strongest mineral cement known. At first the mass is soft 
and of little coherence, but in six months' time it will, if 
pressed, become so hard as to strike fire from steel. 

A free application of soft soap to a fresh burn almost 
instantly removes the fire from the flesh. If the injury is 
very severe, as soon as the pain ceases apply linseed oil, and 
then dust over with fine flour. When this covering dries 
hard, repeat the oil and flour dressing vmtil a good coating is 
obtained. When the latter dries, allow it to stand until it 
cracks and falls off, as it will in a day or two, and a new skin 
will be found to have formed where the skin wa? burned. 

A new form of electrical railway is being erected at St. 
Paul, Minn. The cars do not touch the ground, but are 
suspended from girders which form the track and at the 
same time the mains conveying the current. Speeds of from 
eight to ten miles per hour are expected. 

CELLULOID SHEATHING. 

Among the various uses of celluloid, it would appear to 
be a suitable sheathing for ships, in place of copper, A 
French company now undertakes to supply the substance for 
this at nine francs psr surface meter, and per millimeter of 
thickness. In experiments by M. Butaine, plates of cellulohl 
applied to various ves-^els in January last, were removed fiva 
or six months after, and found quite intact and free from 
marine vegetation, which was abundant on parts uncovered. 
The color of the substance is indestructible; the thickness 
may be reduced to 0.0003 meter; and the ciualities of elas- 
ticity, solidity and impermeability, resistance to chemical 
action, etc., are a!l in favor of the use of celluloid. 



T30 

TRANSMITTING POWER BY A VACUUM. 

The idea of producing a vacuum in a receiver or in a sys- 
tem of pipes, and utilizing this vacuum to transmit power, 
was put forth many years ago. In an article published in 
1688 Papin recommends the use of this mode of transmission. 
He mentions its advantages, particularly its simplicity and 
convenience ; he gives for different cases, the proper diameters 
of the pipes in which the vacuum is made, and recommends 
lead as the material from which to make them. The idea is 
therefore old, but it is only recently that it has been put into 
practice. There is now a central station running on this prin- 
ciple in Paris, distributing 250 h. p. by means of pipes in 
which a seventy-five per cent, vacuum is maintained. One 
year ago. the company running this station had fifty custom- 
ers ; now there are 105 leases signed. 

The possibility of maintaining a vacuum in an extensive 
system of pipes has sometimes been questioned. Repeated 
experiments, however, have shown that in a line of pipes a 
third of a mile long a pressure of a quarter of an atmosphere 
can be maintained so that two gauges, one at each end of the 
pipe, stand at exactly the same point. 

In the station at Paris the exhauster is operated by a 
Corliss engine of special construction, the speed of which is 
automatically controlled by a regulator operated by the 
variations in pressuire in the main pipe. 1 n^: branch pipes are 
of lead, and are of different diameters, according to the num- 
ber of consumers that each is to supply. Each of these branch 
pipes is provided with a cock that can be opened or closed by 
means of a wrench that is kept at the central station. The 
smaller branches that supply the individua,! customers are also 
of lead, and are likewise provided with cocks that can be 
opened or closed only by the employes of the company, who 
retain possession of the wrenches that open them. 

Two kinds of motors are in use, one, the rotary class, 
bemg used for the smaller powers; the other class, which have 
cylinders and pistons, being used only for larger powers. The 
small motors have an efficiency of about 40 per cent., while 
in the largest size the ef&ciency is said to be as high as 80 per 
cent. 

SPONTANEOUS COMBUSTION. 

No one of average intelligence and information now 
believes in the possibility of human beings or the lower ani- 
mals undergoing spontaneous combustion ; and yet it is 
barely forty years since Liebig devoted a long chapter of his 



137 

celebrated " Familiar Letters on Chemistry '* to exposing the 
fallacy of this idea, thus showing that at that date it was preva- 
lent. Every reader of Dickens will remember that in one of 
his most interesting stories an important episode is made to 
turn on the popular belief in spontaneous combustion, a belief 
which Dickens himself would seem to have shared. Of 
course, as Liebig points out, it requires no explanation 
to account for the connection which has often been shown 
to exist between death by burning and the too frequent indul- 
gence of ardent spirits. Spontaneous combustion, though 
not of living animals, may, however, occur in certain cases, 
and give rise to fires in buildings, etc., and it may, therefore, 
be of interest to the reader to examine shortly some of those 
possible cases and their causes. But first of all, a few words 
as to " combustion '* itself, the true nature of which was 
explained by the famous French chemist Lavoisier, toward the 
end of last century. 

An act of combustion is an act of chemical combina- 
tion attended by the evolution of heat and light, and, for such 
an act, two conditions are necessary, viz. : (i) There must 
be a gas in which the given substance will burn, i. e. with 
which it will combine chemically, and (2) there must be a 
certain temperature, the degree of temperature being different 
for each different substance. Thus, to take only one common 
example, a piece of coal will remain unaltered, at the ordi- 
.^ary temperature of the air, for practically an unlimited 
period of time; but, if it be heated to a sufficiently high 
temperature, it will burn. /. ^. , the carbon of which it is com- 
posed will combine with the oxygen of the air, to form car- 
bonic acid gas; chemical combination goes on in this case 
so rapidly, comparatively speakmg, that the heat and light 
set free by it are palpable to our senses. Now, the two 
requisite conditions just mentioned sometimes occur together 
in nature, giving rise to true cases of spontaneous combustion, 
f if which the following examples may be cited : 

1. T\iQigmsfatiins, or *' will-o'-the-wisp," is the effect 
pf the spontaneous ignition of a volatile compound ofphos- 
•)horus and hydrogen, which is generated, under certain con- 
ditions, from decomposing animal and vegetable matter. 
This compound has such an intense affinity for the oxygen of 
the air, that, the moment it comes in contact with the latter, 
it ignites of itself, giving out the flash of light that has de- 
luded so many a wanderer. ^ 

2. Spontaneous combustion also occurs not unfrequently 
in coal ships, or in the coal bunkers of ordinary vessels. ^ Coal 
ijenerally contains iron pyrites or " coal brasses " disseminated 



138 

t!irough it, and this pyrites, which is a compound of iron and 
sulphur, has a great tendency to absorb oxygen from the air 
and to combine with it, forming sulphate of iron, or " green 
vitriol. " This absorption and combination are accompanied 
by a rise of temperature, and they sometimes go on so rapidly 
as to raise the temperature of the mass sufficiently high to 
cause the coal to catch fire. 

3. Fires in buildings are often to be traced to the presence 
of heaps of old cotton waste. Such waste is always more or 
less impregnated with oil, and, being very loose in texture, it 
exposes a large surface to the air. The result is that the oil 
rapidly absorbs and combines chemically with the oxygen of 
the air, just as the pyrites in coal does, raising the temperature 
to such a degree that a fire ensues. 

4. The " heating of corn M'hich has been stacked before 
the she-ccv^es have been sufficiently dried, and which sometimes 
ends in the corn stack catching fire, is the result of chemical 
changes of the nature of fermentation. 

5. Every one must have observed what a large amount 
of heat is set free when lime is slacked ■ — so much, indeed, 
that fires have frequently been known to result from it. The 
reason of this is, that the lime combines with a certain pro- 
])ortion of water, this act of combination causing much heat 
^o be liberated. 

The above instances are sufficient to show that sponta« 
neous combustion in no way differs from ordinary combustion, 
excepting in that the requisite temperature is attained by 
natural causes, and not artificially, and that the old idea held 
by the superstitions of last century, that the spontaneous 
combustion of animals (which we now know to be impossi- 
ble) was caused by a peculiar kind of fire, differing from ordi- 
nary fire, ana not extinguishable by water, was the result of 
ignorance. There is still one other cause of spontaneous 
combustion, often very dangerous in its effects, and which 
leads us on to the subject of explosions, which must be men- 
tioned here. One occasionally reads in the newspapers of 
explosions occurring in flour mills, sometimes from no appar- 
ent cause. These explosions are cases of rapid sponta- 
neous combustion, in which a spark from the grindstone sets 
fire to the fine flour dust with which the air of the mill is 
impregnated. 

But what is an " explosion "? An explosion is nothing 
more nor less than a combustion which spreads with great 
rapidity throughout the whole mass of the combustible matter. 
To our senses it appears to be instantaneous, but it is not really 
80. An example will make this clear. A mixture of hydrogen 



139 

said oxygeii, or hydrogen and air, is a highly dangerous one, 
because the instant that a hght is introduced into it it explodes ; 
that is to say, the particles of hydrogen and oxygen in the 
immediate neighborhood of the flame are raised to the requisite 
temperature at which chemical combination can take place 
between them. They therefore do combine to form water 
vapor, and, by doing so, give out heat enough to cause com- 
bination between the particles next to them, and so on 
throughout the whole mass of the gas. This action goes on, 
as already stated, so rapidly as to be practically instantaneous. 
The terrible effects of explosions are caused, then, by the 
sudden production of immense quantities of hot gases. The 
newspapers constantJy tell us of disastrous explosions resulting 
from the bringing of a light into a room in which an escape of 
gas is going on. A mixture of coal gas and air behaves 
in precisely the same manner as the mixture of hydrogen 
and oxygen, or hydrogen and air, mentioned above, with 
the exception that the. products of the combustion or ex- 
plosion are different. When an escape of gas is suspected, all 
lights should be rigorously excluded, the gas turned off at the 
meter or main, and windows and doors opened, so as to get 
rid of the already-escaped gas as quickly as possible ; and only 
then, after complete ventilation has taken place, may a light 
be brought into the room with safety. It is to be hoped that 
such a technical instruction bill will soon be passed by parlia- 
ment as will render avoidable accidents of this nature less and 
less likely to occur. It is likewise a dangerous thing to blow out 
a parafhne lamp instead of turning the wick down, as, by blow- 
ing the flame downward, one is apt to ignite the mixture of 
oil, gas and air which is in the upper portion of the oil reser- 
voir, and so to produce a serious explosion. 

The explosion caused by the ignition of gunpowder or any 
other ordinary explosive, is explicable in the same way, bu* 
can only be touched upon in this article. Gunpowder is a 
most intimate mixture of charcoal, sulphur and nitre (potassic 
nitre), the last named substance being a compound containing 
a very large percentage of oxygen, which can be liberated on 
heating it. On applying a light to gunpowder, we raise the 
temperature sufficiently to allow of the carbon and sulphur 
burning in the oxygen liberated from the nitre; and, since the 
three substances are so intimately mixed together, this com- 
bustion proceeds with explosive rapidity, and produces a rela- 
tively enormous quantity of hot gas. 

Steel, when hardened, decreases in specific gravity, con- 
tracts in length and increases in diameter. 



I40 
RULES FOR THE FIREMAN. 

In the care and management of the steam boiler tht 

first thing requu'ed is an unceasing watchfulness — ',vatch- 
care is the very word which describes it. The accidents 
arising from neglect or incompetency in care of the engine 
are few and unimportant compared to those which come 
from negligence in attending to the boiler. 

Hence the fireman needs to be a man possessed of some 
of the highest qualities of manhood. The fact that many of 
the best steam engineers in the countiy have begun their 
careers by handling the shovel is evidence that good men 
are required and employed in this capacity, and that they 
are rewarded for their faithfulness by advancement. 

An intemperate, reckless or indifferent man should never 
be given this place of trust. The sooner a man is dismissed 
who is either of these the better, both for himself and his 
employers, to say nothing of the innocent and unsuspecting 
public. ^ 

A.n employer should know something of the character 
and habits of the man who does the firing. A daily visit, 
and, at irregular times, with an eye to things in the boiler- 
room^ as well as the engine-room, will keep him posted, to 
his great advantage. This regular inspection is most wel- 
come to faithful and careful men, and is a great inspiration 
to good service. A steam-user should visit his steam depart- 
ment as regularly as he does his office, although he may not 
spend as much time there. The failure of scores of other- 
wise flourishing establishments is due to the waste and 
recklessness in the use of fuel under the boilers, or the 
heavy losses incurred by repairs and explosions — by which 
the whole business is stopped while the expenses continue 
undiminished. 

A feeling of conscientious responsibility should be the 
uppermost thing upon the mind of a fireman when on duty. 
He should consider and know how to figure the total tons of 
pressure upon the plates of his boiler, and have constantly in 
mind the importance of unceasing vigilance. 

To know how to be a good fireman cannot be taught by 
a book. The knowledge comes by experience and by instruc- 
tion of engineers who have themselves been good firemen, 
but the following are some of the hints and rules which may 
be of advantage to the new beginner. 

First — The fireman should be a sober and tempf?rate 
person. Frivolous or reckless conduct about a steam-boiler 
^entirely out of place, and should not be permitted. There 



X4S 

ts too mucli clanger and too much cost — not to call it 
waste — of fuel to allow any indifference or recklessness in 
the man upon whom so many depend. 

Second — The fireman should be punctual in beginning 
[lis work. A loss of five minutes in starting into vigorous 
ictivity the men and machines of an establishment is some- 
times caused by inattention of the fireman, and the blame 
which is showered upon him is a stern reminder that he is 
leld accountable for the loss. 

Third — A habit of neatness is an almost necessary qual- 
ty, and which pays better for the cost of investment than 
my other. 

Fourth — The tools should be kept in their places, and 
m good order. 

Fifth — The boiler and all its attachments should be kept 
n the very tidiest and attractive condition possible. 

Sixth — The fireman, notwithstanding its apparent diffi- 
;ulty, should keep himself — as said once — "respectable 
ibout his work. " Scattered coal and ashes and dripping oil 
ihould be constantly cleaned up, and every effort made to 
iiake the boiler-room an attractive and cheerful place. 

Seventh — The fireman needs to know all the details of 
lis work, and to dp with exactness every duty imposed upon 
lim. He needs to be cool and brave in the presence of 
imexpected conditions, such as sudden leaks, breakages of 
the glass gauges and sudden stoppages of the engine with a 
leavy head of steam on. 

Eighth — He should have ^n idea of the importance of his 
work, and keep in mind to learn to do everything that may 
fit him in time for an advanced position. 

GRAPHITE IN STEAM-FITTING. 
Few steam-fitters or engineers understand the valuable 
properties of graphite in making up joints; this valuable 
mineral cannot be overestimated in this connection. Inde- 
structible under all changes of temperature, a perfect lubri- 
cant and an anti-incrustator, any joint can be made up per- 
fectly tight with it and can be taken apart years after as easy 
as put together. Rubber or metal gaskets, when previously 
smeared with it, will last almost any length of time, and will 
leave the surface perfectly clean and bright. Few engineers 
put to sea without a good supply of this valuable mineral, 
while it seems to be almost overlooked on shore. 



i 142 

HORSE POWER — NOMINAL, INDICATED AND 
EFFECTIVE, WITH RULES FOR DETERMIN- 
ING THE HORSE POWER OF AN ENGINE. 

Engineers and others who never carefully considered 
the matter, often use the three terms above as synonymous. 
While the terms are far from having a like meaning, still we 
often hear the nominal horse power of a steam engine spoken 
of when the person using the expression really means the 
indicated powei. To show the distinctive difference between 
the meanings of the words nominal, indicated and effective, 
as applied to the term horse power, is our aim. 

A horse power is merely an expression for a certain, 
amount of work, and involves three elements — force, space 
and time. If the force be expressed in pounds and the space! 
passed through in feet, then we have a solution of, and] 
meaning for, the term foot-pound; from which it will bei 
seen that a foot-pound is a resistance equal to one pound' 
moved through a vertical distance of one foot. The work 
done in lifting thirty pounds through a height of fifty feet is 
fifteen hundred foot-pounds. Now, if the foot-pounds 
required to produce a certain amount of work involve a 
specified amount of time during yrlvlch the work is performed, 
and if this number of foot-pounds is divided by the equiva- 
lent number representing one horse power (which number 
will depend upon the time), then the resulting number will 
be the horse power developed. 

For example, suppose the 1,500 foot-pounds just spoken 
oi to have acted in one second. To find the horse power 
divide by 550, and the result will be the horse power. 

A horse power is 33,000 foot-pounds per minute; or, in 
other words, 33,000 pounds lifted oiic foot in one minute, or 
one pound lifted 33,000 feet in one minute, or 550 pounds 
lifted one foot in one second, etc. 

The capacity for work of a steam engine is expressed in 
the number of horse powers it is capable of developing. 

Nominal horse power is an expression which is gradually 
going out of use, and is merely a conventional mode of 
describing the dimensions of a steam engine for the con- 
venience of makers and purchasers of engines. The mode 
of computing the so-called nominal horse power was estab- 
lished by the practice of some of the early English manu- 
facturers, and is as follows : ^ 

lAssume the velocity of the piston to be 128 feel ^er 
minute multiplied by the cube root of length of stroke in feet. 

Assume the mean effective pressure to be seven pound* 



143 

per square inch. From these fictitious data and the area c4 
the piston compute the horse power ; that is, nominal horse 
power=7 X 128 X*^ \f stroke in feet X area of piston in 
square inches-f-33,ooo. 

Indicated horse power is the true measure of the work 
done within the cyhnder of a steam engine, and is based upon 
no assumptions, but is actually calculated. The data neces- 
sary are : The diameter of the cylinder in inches, length in 
feet, the mean effective pressure and number of revolutions 
per minute. As we have before stated, or implied, work is 
force acting through space, and a horse power is the amount 
of work in a specified time. In a steam engine the force 
which acts is the product of the area of the piston in square 
inches muhiplied by the mean effective pressure ; the space 
is twice the stroke in feet, or one complete revolution, mul- 
tiplied by the number of revolutions per minute. 

Therefore, indicated horse power equals the area of the 
piston, multiplied by the mean effective pressure, multiplied 
by the piston speed in feet per minute divided by 33,000. 

Effective horse power is the amount of work which an 
engine is capable of performing, and is the difference be- 
tween the indicated horse power and horse power required 
to drive the engine when it is running unloaded. 

Engine rating, guarantees, etc., are usually based upon 
the indicated horse power, owing to the ease and accuracy 
with which it can be determined, and as a means of com- 
parison. 

Nominal horse power is computed from fictitious data. 

Indicated horse power is computed from actual data, 
which is arrived at by means of what is known as the steam 
engine indicator. 

Effective horse power is computed from actual data, 
either by means of the indicator, brake or dynamometer, 

THE CARE OF MACHINERY. 

The money spent in keeping machinery clean and in 
order is by no means wasted. The better the machinery, 
the greater the necessity for proper supervision. The first 
knock in an engine, the smallest leak in a boiler, the slight- 
est variation from truth in a mill spindle, the wearing down 
of roller bearings, heating of journals, should be rectified 
immediately. The smooth and even working of machinery 
has a great deal to do with the cost of driving, while avoid- 
ance of the risk of breakage saves a large sum that would 
otherwise be spent in 1 epairs. 



144 
FOAMING IN BOIJ.ERS. 

The causes are dirty water; tryirig to evaporate more 
water than the size and construction d' the boiler is intended 
for; taking the steam too low down; insufficient steam 
room; imperfect construction of boiler, and too small a 
steam pipe. 

Take a kettle of dirty water and place it on a fire and 
allow it to boil and watch it foam, and it will be the same in 
a boiler. 

Too little attention is paid to boilers with regard to 
their evaporating power. Where the boiler is large enough 
for the water to circulate, and there is surface enough to 
give oft the steam, foaming never occurs. As the particles 
of steam have to escape to the surface of the water in the 
boiler, unless that is in proportion to the amount of steam 
to be generated, it will be delivered with such violence that 
the water will be mixed with it and cause what is called 
foaming. 

A high pressure insures tranquillity at the surface, and, 
the steam itself being more dense, it comes away in a more 
compact form, and the ebullition at the surface is no greater 
than a*: a lower pressure. When a boiler foams, we close 
the throttle to check the flow, and tliat keeps up the pres- 
sure and lessens the sudden delivery. 

Too many flues in a boiler obstru^ c the passage of the 
cvtam from the lower part of the boiler on its way to the 
surface; this is a fault in construction, but nearly all foaming 
arises from dirty water, or from trying to evaporate too 
much water without heating surface or steam room enough. 
Usually, when first put in, a boiler and engine are large 
enough, but, as business increases, more machinery is added 
until the power required is greater than can be furnished by 
the engine, more pressure has to be carried, and the number 
of revolutions increased; consequently the evaporating 
power of the boiler is forced beyond its ability, the steam 
being drawn off so rapidly that a large portion of water is 
drawn with it — so much that it would astonish any engineer 
if he had a testing apparatus attached to the steam pipe. 

For the remedy of foul water there are numerous con- 
trivances to prevent it from entering the boiler, which is a 
far better way than trying to extract ^he sediment after it is 
there — though there are many ingenious methods for doing 
that also. ^Faulty construction, or lack of capacity, the 
engineer cannot help, but he soon learns how to run the 
boiler to get the best possible results from it. 



145 

Every intelligent engineer has observed that his engine 
has an individuality not possessed by any other he ever ran, 
and nothing but personal acquaintance can get the best work 
out of it; so it is with the boiler. 

The steam pipe may be carried through the flange six 
inches into the dome, which would prevent the water from 
entering the pipes by following the sides of the dome as it 
does. 

For violent ebullition a plate hung over the hole where 
the steam enters the dome from the boiler is a good thing, 
and prevents a rush of water by breaking it when the throttle 
is opened suddenly. 

Clean water, plenty of surface, plenty of steam room, 
large steam pipes, boilers large enough to generate steam 
without forcing the fires, are all that is required to prevent 
foaming. A surface blow-off is a grand thing, and helps a 
foaming boiler, and would be a good thing on every boiler, 
as you can then skim it as you would an open kettle. 

HAND-HOLE PLATES. 

They should be placed in such a position as to be accessi- 
ble and at or near all those parts of the boiler where scale or 
sediment is liable to accumulate In the locomotive station- 
ary boiler there should be one in each outside corner of the 
fire box and above the bottom ring, and one in each head 
under the tubes. In the upright tubular there should be at 
least two hand-hole plates above the ring, and one over the 
furnace door, on a line with the lower tube sheet, as in the 
locomotive boner. The horizontal boiler should have one 
in each head under the tubes, and the rule generally observed 
is, that, whenever sediment is deposited, then there should be 
a hand-hole to get at it for a regular cleaning out. 

These plates should be removed once a month, or oftener 
if necessary, to keep them clean, and are never considered 
an article of ornament, but of primary importance. 

BOILING. 

Let it be remembered, that the boiling spoken of so often 
is really caused by the formation of the steam particles, and 
that, without the boiling, there can be but a very slight quan- 
tity of steam produced. 

While ]nire water boils at 212°, if it is saturated with 
common salt, it boils only on attaining 224^, alum boils at 
220°, sal ammoniac at 236^^ acetate of soda at 256^^ pure 
nitric acid boils at 248^^ and jnu-e sulphuric acid at 620"^. 



14^ 
INCRUSTATION OF STEAM BOILERS. 

One of the greatest difficulties to be contended against in 
steam engineering is the incrustation on the boiler walls, aris- 
ing from impure water. This crust is a poor conductor of heat^ 
and causes increased fuel consumption, as well as the oxidiz- 
ing or " burning " of the plates, owing to their increased tem- 
perature. A plate of iron 37^ inches thick conducts heat as 
well as a " crust " of one inch. A boiler bearing scale only 
I -16 inch thick requires 15 pei cent, more fuel, with % inch 
60 per cent, more, ^ inch 150 percent, more. If the plates 
be clean, 90 pounds of steam require a plate temperature of 
only 325^ F. ; that is, about 5^ above the steam tempera- 
ture. But if there be a ^ inch scale or crust, the plate 
must be heated to about 700^, or nearly *' low red " heat. 
Now, about 600° iron soon gets granular and brittle; hence 
such a scale is dangerous in its results. Crust also retards 
the circulation of the water. Two very common ingredi- 
ents in boiler scale are carbonate of lime and sulphate of 
lime, or gypsum. The moderate use of soda ash (say one 
part in 5,000 of water) holds this deposit in check, by pro- 
ducing from the principal ingredients a -.teutral carbonate of 
lime, which will not adhere to the plates, when thus rapidly 
formed. Soda ash, if used in excess, boils up and passes 
into the cylinders and pumps, clogging up valves and pistons 
by combining with the lubricants. If the gauge-glasses 
become muddy, too much soda water is used. It is much 
better to supply the boilers with pure water that can deposit 
no scale, this being done by means of filters and heaters, or 
by surface-condensers, and being especially advisable with 
sectional and w^ater tube boilers. 

SUPERHEATED STFAM. 

Superheated steam is made by drawing steam from the 
boiler and heating it after it has ceased to be in contact with 
the water in the boiler. The apparatus by which the extra 
heat is imparted is called a super-heater. The steam is con- 
ducted through the pipes, and hot air and gases of combus- 
tion are passed around the outside of them, thus raising the 
temperature and forming a more perfect gas. 

STEAM GAUGES. 

Steam gauges indicate the pressure of steam above the 
atmosphere, the total pressure being measured from a per- 
fect vacuum, which will add 14 7-10 pounds on the average 
to the pressure shown on the steam gauge. 



147 

IMPORTANT TO THOSE OPERATING STEAM 
BOILERS. 

In view of the numerous boiler explosions that have 
recently occurred, we submit to them the following perti- 
nent questions asked by the A7ne7Hcan Machmist^ which 
should command the careful consideration of every steam 
user in the land: 

How long since you were inside your boiler? 

Were any of the braces slack? 

Were any of the pins out of the braces? 

Did all the braces ring alike? 

Did not some of them sound like a fiddle-string? 

Did you notice any scale on flues or crown sheet? 

If you did, when do you intend to remove it? 

Have you noticed any evidence of bulging in the fire-box 
plates? 

Do you know of any leaky soc* ot bolts? 

Are any of the flange joints leaking? 

Will your safety valve blow off itself, or does it stick a 
little sometimes? 

/Vre there any globe valves between the safety valve and 
the boiler? They should be taken out at once, if there are. 

Are there any defective plates anywhere about your 
boiler ? 

Is the boiler so set that you can inspect every part of it 
when necessary? 

If not, how can you tell in what condition the plates are? 

Are not some of the lower courses of tubes or flues in 
your boiler choked with soot or ashes? 

Do you absolutely know, of your own knowledge, that 
your boiler is in safe and economical working order, or do 
you merely suppose it is? 

HOW TO PREVENT ACCIDENTS TO BOILERS. 

I St. Carry regular steam pressure. 

2d. Start the engine slowly so as not to make a violent 
change in the condition of the water and steam, anc^ when 
consistent, stop the engine gradually. 

3d. Carry sufficient water in the boiler. 

4th. Do not exceed the pressure in pounds per square 
infh allowed to be carried. 

5th. See that every appliance of the boiler, feed pipes 
and safety-valve, fusible plugs, etc., are in complete working 
order. 



148 

PRINCIPLES ON WHICH BOILERS AND THEIR 
FURNACES SHOULD BE CONSTRUCTED. 

Hitherto, those who have made boiler-making a sepa- 
rate branch of manufacture, have given too much attention 
to mere relative proportions. One class place reliance on 
erilarged grate surface, another on large absorbing surfaces, 
while a third demand, as the grand panacea, " boiler-room 
enough," without, however, explaining what that means. 
Among modern treatises on boilers, this principle of room 
enough seems to have absorbed all other considerations, and 
the requisites, in general terms, are thus summed up : 

1. Sufficient amount of internal heating surface. 

2. Sufficient roomy surface. 

3. Sufficient air-space between the bars. 

4. Sufficient area in the tubes or flues ; and 

5. Sufficiently large fire-bar surface. 

In simpler terms, these amount to the truism — give suf- 
ficient size to all the parts, and thus avoid being deficient 
in any. 

With reference to the proportions of the several parts of 
a furnace, there are two points requiring attention ; fiist, 
the superficial area of the grate for retaining the solid fuel 
or coke ; and, second, the sectional area of the chamber 
above the fuel for receiving the gaseous portion of the coal. 

As to the area of the grate-baj^s, seeing that it is a 
solid body that is to be laid on them, requiring no more 
space than it actually covers at a given depth, it is alone 
important that it be not too large. On the other hand, as 
to the area of the chamber above the coal, seeing that it is 
to be occupied by a gaseous body, requiring room for its 
rapidly enlarging volume, it Js important that it be not too 
small. 

As to the best proportion of the grate, this will be the 
easiest of adjustment, as a little observation will soon enable 
the engineer to determine the extent to which he may 
increase or diminish the length of the furnace. In this 
respect the great desideratum consists in confining that 
length within such limits that it shall, at all times, 
be well and tmiformly covered. This is the absolute 
condition and sine qua non of economy and efficiency; 
yet it is the very condition which, in practice, is the 
most neglected. Indeed, the failure and uncertainty which 
has attended many anxiously conducted experiments has most 
■frequently arisen from the neglect of this one condition. 

[f the grate-bars be not equally and well covered, the 



149 

Air will enter in irregular and rapid streams or masses, 
through the uncovered parts, and at the very time when it 
should be there most restricted. Such a state of things at 
once bids defiance to all regulation or control. Now, on the 
control of the supply of air depends all that human skill can 
do in effecting perfect combustion and economy ; and, until 
the supply of fuel and the quantity on the bars be regulated, 
it will be impossible to control the admission of the air. 

Having spoken of the grate-bar surface, and what is 
placed on it, we have next to consider the chamber 
part of the furnace, and what is formed therein. In marin? 
and cylindrical land boilers, this chamber is invariably made 
too shallow and too restricted. 

The proportions allowed are indeed so limited as to give 
it rather the character of a large tube, whose only function 
should be, the allowing the combustible gases to pass through 
it, rather than that of a chamber, in which a series of consecu- 
tive chemical processes were to be conducted. Such 
furnaces by their diminished areas, have also this injurious 
tendency, — that they increase the already too great rapidity 
of the current through them. 

The constructing the furnace chamber so shallow an\ 
with such inadequate capacity, appears to have arisen from 
the idea, that the nearer the body to be heated w^as brought 
to the source of heat, the greater would be the quantity 
received. This is no doubt true w^hen we present a body to 
be heated in front of a fire. When, however, the approach 
of the colder body will have the direct effect of interfering 
with the processes of nature (as in gaseous combustion), it 
must manifestly be injurious. Absolute contact with flame 
should be avoided where the object is to obtain all the heat 
which would be produced by the combustion of the entire 
constituents of the fuel. 

So much, however, has the supposed value of near ap- 
proach, and even impact, prevailed, that we find the space 
behind the bridge, frequently made but a few inches deep, 
and bearing the orthodox title of the flame-bed. Sounder 
views have, however, shown that it should be made capa- 
cious, and the impact of the flame avoided. 

As a general view, deduced from practice, it mav r>e 
stated that the depth between the top of the bars and tne 
crown of the furnace should not be less than two feet si* 
inches where the grate is but four feet long ; increasing \n 
the same ratio where the length is greater ; and secondiy, 
that the depth l^elow the bars should not be less, although 
depth there is not so essential either practically or chemicaliy. 



I50 





PROPERTIES 


OF SATURATED 


STEAM 


• 


PRESSURE. 




Volume. 




Total heat 














required 






Tempera- 






Latent 


to generate 






ture in 






Heat in 


T lb. of 


Steam 
Gauge. 




Fahrenheit 


Com- 


Cubic Feet 


Fahren- 


Steam from 


Total 


Degrees 


pared 

with 

Water. 


of Steam 
from I lb. 
of Water. 


heit 
Degrees. 


Water at 32 

dcig. under 

constant 














pressure. 














In Heat 

Units. 


o 


15 


212.0 


1642 


26.36 


965.2 


1146. I 


5 


20 


228.0 


1229 


19.72 


952.8 


1150.9 


o 


25 


240.1 


996 


15.95 


945-3 


1154-6 


iS 


30 


250.4 


838 


13-46 


937-9 


1157-8 


20 


35 


259-3 


726 


11.65 


931.6 


1160,5 


25 


40 


267.3 


640 


10.27 


926.0 


I 162. 9 


30 


45 


274.4 


572 


9.18 


920.9 


I I 65. I 


35 


50 


281.0 


518 


8.31 


916.3 


1167.1 


40 


55 


287.1 


474 


7.61 


912.0 


I I 69.0 


45 


60 


292.7 


437 


7.01 


908.0 


1170.7 


50 


65 


298.0 


405 


6.49 


904.2 


IT72.3 


55 


70 


302.9 


378 


6.07 


900.8 


1173-8 


60 


75 


307-5 


353 


5.68 


897-5 


1175.2 


65 


80 


312.0 


333 


5 35 


894-3 


1176.5 


70 


85 


316.1 


314 


5.05 


891.4 


1177.9 


75 


90 


320,2 


298 


4.79 


888.5 


1179-1 


80 


95 


324.1 


283 


4.55 


8858 


1180.3 


85 


100 


327-9 


270 


4-33 


883.1 


1181,4 


90 


105 


331-3 


257 


4.14 


880.7 


T182.4 


95 


ITO 


334-6 


247 


3-97 


878.3 


1183.5 


TOO 


115 


338.0 


237 


3-80 


875.9 


1184.5 


no 


125 


344.2 


219 


3.51 


871.5 


1186,4 


120 


135 


350.1 


203 


3.27 


867.4 


1188.2 


130 


145 


355-6 


190 


3.06 


863.5 


1189.9 


140 


155 


361.0 


179 


2.87 


859-7 


1191.5 


150 


165 


366.0 


169 


2.71 


856.2 


1192.9 


160 


175 


370.8 


159 


2.56 


852.9 


1194.4 


170 


185 


375-3 


151 


2.43 


849.6 


1195-8 


180 


195 


379-7 


144 


2.31 


846.5 


1197.2 



This table gives the value of all properties of saturated 
steam required in calculations connected with steam boilers. 

SODA ASH IN BOILERS. 

An English boiler inspection company recommends that 
soda ash be used to prevent scale, instead of soda crystals; 
and that it be pumped in regularly and continuously in solu- 
tion, with the feed, instead of spasmodically dumped in solid 
through the manhole. Tungstate of soda, instead of either 
soda ash or soda crystal, has been recommended strongly by 
some high authorities in lieu "^ the above. 



*5^ 

STEAM COAL. 

Steam coal, being, as everybody knows, unquestionably 
the most important and largest expense in the manufacture 
of steam, is deserving a most careful investigation by engi- 
neers and owners, who, unlike chemists and college pro- 
fessors, consider the subject wholly in a practical way, as 
relating to the coal bills of their establishments. 

Useful knowledge of every-day economy of coal is seldom 
gained by " tests" conducted by experts, for several reasons so 
plain that they will not require explanation, ist. The cost of 
the fuel used in tests, whatever may be stated, is too high, aver- 
age or " every-day " coal not being used. The experiments 
are made with picked men and picked fuel, for brief periods, 
with everything at its best, and the results attained, if looked 
for in the ordinary run of business, will be disappointment 
in the results of the wholesale order. 2d. Men, working as 
firemen, twelve or fourteen hours per day in the hot furnace 
rooms, cannot be expected, with the ordinary appliances, to 
watch where every lump of coal falls when feeding the fur 
naces, nor to clean the grates any oftener than they are com- 
pelled to do. 3d. Moreover, too many employers favor the 
low wages plan, and, for the apparent saving of a few dol- 
lars per month, waste many times the amount in the^.r fur- 
nace doors, and render their establishments most disagree- 
able to their neighbors, by a free distribution of unconsumed 
carbon, or what is commonly called soot, and of which most 
people have no appreciation. 4. Little or no encourage- 
ment is given for careful or economical firing, as a rule. 
The fireman who oftentimes wastes as much as his entire 
wages, secures the same pay as the man working. alongside 
of him who saves it all. It may be remarked that this is 
" not business," but many are the concerns who run their 
steam plants upon this system. Careful handling of coal in 
firing pays better than any other thing about a steam plant, 
and it is the wisest economy to secure good and careful men 
lo do it. 

As is well understood, the conditions or circumstances 
attending the combustion of coal for steam purposes, embra- 
ces a wide range. A very few establishments work under 
conditions that admit of a high attainment of economy by 
having a fixed performance of duty, and their plants well 
proportioned to the regular work, but by far the largest 
number having a fluctuating demand for steam, and in that 
respect are largely at a disadvantage. Many furnaces are 
badly constructed, others suffer from an insufficiency of 



152 

draft, and in many cases there seems to be no end of compli- 
cations detrimental to best results^. 

These practical difficulties and uncertainties, which are well 
known to every experienced engineer, render any investiga- 
tion worthy of the name, slow and laborious. It has taken 
considerable time and research to arrive at the conclusion, 
though differing from the preponderance of hearsay 
or guess-work evidence, that now, at least, " the highest 
priced coal is not the cheapest for steam prodiiction^'''^ 
and that, in fact, the reverse is undoubtedly true, especially 
in the Western country Late improvements in the con- 
struction of grate bars ha^e undoubtedly added largely to 
the value of Western soft coals. The great difficulty, in 
former times, of ridding the furnaces of the incombustible 
part of these very valuable coals has now been removed by 
improvements, and there is no doubt but what a large num- 
ber of extensive establishments in the West are now, and for 
some time past have been, obtaining the same duty from the 
Illinois bituminous coals that they in former years obtained 
from the high-priced Eastern coals. 

BLOWING OFF UNDER PRESSURE. 

A boiler can be seriously impaired by blowing it down 
under a high pressure, and with hot brick work. The heat 
from the latter will granulate the iron and reduce its tensile 
strength. A boiler should not be blown right down under 
a higher pressure than twenty pounds, and not less than four 
hours after /he fire has been drawn. 

When a boiler is exposed to cold air, especially in the 
winter, it js advisable that the damper be closed and the 
doors thrown open, or vice-versa. If both are left open, 
the strong draught of cold air will cool off the flues faster 
than the shell; which abuse, if kept up, would reduce the 
length of the life of the boiler. 

THE TOTAL PRESSURE. 

A boiler eighteen feet in length by five feet in diameter, 
with forty-four inch tubes, under a head of eighty pounds of 
steam, has a pressure of nearly 113 tons on ea^h head, 1,625 
tons on the shell and 4,333 tons on the tubes, making a total 
of 6,184 tons on the whole of the exposed surfaces. 

This calculation is made by finding the total square inches 
under pressure, and multiplying the totals by the pressure, in 
ihis case, 80 i^ounds to the square inch. 



153 



'able Showing Safe Working Steain Pressure for Iron 
Boilers of different sizes, using a Factor of Safety of Six. 



f. 



\ 

X 

'A 

h 
X 

1 fi 

X 

5. 
16 

% 

y% 

X 

h 

v% 

1 

IG 
IB 

7. 
1 « 

^8 



4 

34 



Longitudinal Seams, 
Single Riveted. 



Tensil Strength of Iron 



INCH. 

X 
A 



45,000 


50,000 


Lbs. 


Lbs. 


Press- 


Press- 


ure. 


ure. 


LBS. 


LBS. 


104 


ir6 


130 


145 


99 


no 


123 


137 


94 


104 


117 


130 


89 


99 


112 


124 


B5 


95 


107 


118 


82 


91 


102 


113 


78 


87 


98 


109 


118 


131 


75 


83 


94 


104 


112 


125 


72 


80 


90 


100 


108 


120 


87 


96 


104 


116 


121 


135 


78 


87 


94 


104 


109 


121 


85 


95 


99 


in 


112 


117 


78 


87 


91 


102 


102 


117 



55,000 
Lbs. 

Press- 
ure 



LES. 

127 

159 
121 

151 
115 

143 
109 
136 
104 
130 
1 03 

125 

96 
120 

144 
92 

115 

138 

88 
no 
132 

106 

127 
148 

95 
115. 
134 
104 
121 
138 

96 
n2 
128 



Longitudinal Seams, 
Double Riveted. . 



Tensil Strength of Iron. 



45,000 

Lbs. 


50,000 

Lbs. 


Press- 


Press- 


ure. 


ure. 


LBS. 


LBS. 


156 


139 
174 


119 

148 


132 

164 


113 


125 


140 


156 


107 


119 


134 


149 


102 


114 


128 

98 

122 


142 
109 

136 


94 


104 


n8 


131 


142 


157 


90 


100 


113 


125 


134 

86 

108 


150 

96 

120 


130 


144 


lOI 


n2 


120 
140 


134 
156 


94 


104 


113 


125 


131 


145 


102 


114 


120 


133 


137 


152 


94 


104 


no 


122 


125 


140 



55,000 
Lbs. 

Press- 
ure. 

LBS. 

152 
191 

145 
181 

138 

172 

131 

163 
125 

156 
120 
150 

ii5 

144 
173 
no 

138 
166 
106 
132 
158 
122 
148 
172 

114 

138 
160 
125 
146 
167 

115 
134 
15.^ 



154 

brEAM HEATING. 

The advantages of steam heating are set forth by Prof. 
W. P. Trowbridge, in the No7'th Ainerican Review^ as 
follows : 

1. The almost absolute freedom from risk of fire when 
the boiler is outside of the walls of the building to be heated, 
and the comparative immunity under all circumstances. 

2. When the mode of heating is the indirect system, 
with box coils and heaters in the basement, a most thorough 
ventilation may be secured, and it is in fact concomitant with 
the heating. 

3. Whatever may be the distance of the rooms from the 
source of heat, a simple steam pipe of small diameter con- 
veys the heat. From the indirect heaters underneath the 
apartments to be heated, a vertical flue to each apartment 
places the flow of the low heated currents of the air under 
the absolute control of the occupants of the apartment. 
Uniformity of temperature, with certainty of control, may 
be thus secured. 

4. Proper hygrometric conditions of the air are better 
attained. As the system supplies large volumes of air 
heated only slightly above the external temperature, there is 
but little change in the relative degree of moisture of the air 
as it passes through the apparatus. 

5. No injurious gases can pass from the furnace into the 
air flues. 

6. When the method of heat is by direct radiation in 
the rooms, the advantage of steadiness and control of tem- 
perature, suflicient moisture and good ventilation, are not 
always secured; but this is rather the fault of design, since 
all these requirements are quite within reach of ordinary 
contrivances. 

7. One of the conspicuous advantages of steam heating 
is that the most extensive buildings, whole blocks, and even 
large districts of a city may be heated from one source, the 
steam at the same time furnishing power where needed for 
ventilation or other purposes, and being immediately avail* 
able also for extinguishing fires, either directly or through 
force pumps. 

STOPPING WITH A HEAVY FIRE. 

When it becomes necessary to stop an engine with a heavy 
fire vn the furnace, place a layer of fresh coal on the fire, shut 
tne damper and start the injector or pump for the purpose of 
keeping up the circulation in the boiler. 



155 
ANALYSIS OF BOILER INCRUSTATION. 

BY DR. WALLACE. 

Carbonate of lime 64.98 

Sulphate of lime 9. 33 

Magnesia 6.93 

Combined water . , 3. 15 

Chloride of sodium 23 

Oxide of iron. . . ., „ 1. 36 

Phosphate of lime of alumina 3. 72 

Silica 6.60 

Organic matter 1.60 

Moisture at 212 degrees F 2.10 



100. 
CLEANING BOILER TUBES. 

The method of cleaning boiler tubes depends upon the 
kind of fuel used. A steam jet will not answer where wood 
and soft coal are used, but will do for hard coal, though in 
any case a scraper is indispensable, where a steam jet is not. 
Soot and dust will collect in the tubes and burn on so as to 
require more than a jet of steam to move it. A steam jet or 
blower should be used only where dry steam is at hand, but 
by no means with wet steam. Before using the jet, thor- 
oughly blow all the water out of it and heat it up. We have 
seen some men put the point of the jet in a tube and turn on 
steam before warming, and then wonder what caused the brick 
work to crumble away at the back end . 

CLEANING BRASS. 

The government method prescribed for cleaning brass, 
and in use at all the United States arsenals, is said to be 
the best in the world. The plan is, to make a mixture of 
one part of common nitric, and one-half part sulphuric acid 
in a stone jar, having also a pail of fresh water and a box of 
saw-dust. The articles to be treated are first dipped into 
the acid, then removed into the water, and finally rubbed 
with the saw-dust. This immediately changes them into a 
brilliant color. If the brass has become greasy, it is first 
dipped into a strong solution of potash or soda, in warm 
water. This dissolves the grease, so that the acid ha.*^ power 
to act. 

THE THERMAL UNIT 

Is the heat necessary to raise one pound of water at 39^ F, 
one degree^ or to 40^ F. 



156 
SMOKE — HOW FORMED. 

When fresh coal is placed on a fire in an open grate, 
smoke arises immediately; and the cause of this smoke is not 
far to seek, as it will be easily miderstood that, before fresh 
coals were put upon the fire within the grate, the glowing 
coals radiated their heat and warmed the air above, and 
thereby enabled the rising gases to at once combine with the 
warmed air to produce combustion; but, when the fresh coals 
are placed upon the fire, they absorb the heat, and the air 
above remains cold. 

By gases, is meant the gases arising from coals while on 
or near the fire, and it may not be known to every one that 
we do not burn coals, oils, tallow or wood, but only the 
gases arising from them. This can be made clear by the 
lighting of a candle, which will afford the information 
required. By lighting the candle, fire is set to the wick, 
which, by its warmth, melts a small quantity of tallow 
directly absorbed by the capillary tubes of the wick, and 
thereby so very finely and thinly distributed that the burning 
wick has heat enough to be absorbed by the small quantity 
of dissolved tallow to form the same into gases, and these 
gases burning, combined with the oxygen in the atmosphere, 
give the light of the candle. A similar process is going on 
in all other materials; but coal contains already about sev- 
enteen per cent, of gases, which liberate themselves as soon 
as they get a little warm. The smaller the coal, the more 
rapidly will the gases be liberated, so that, in many cases, 
only part of the gases are consumed. 

The fact is, that the volatile gases from the coal cannot 
combine with cold air for combustion. Still combustion 
takes place in the following ways. The cold air, in the act 
of combination, absorbs a part of the warmth of the rising 
gases, which they cannot spare, and, therefore, must con- 
dense, so that small particles are formed, which aggregate 
and are called smoke, and when collected, produce soot; but 
as long as these particles and gases are floating, they cannot 
burn or produce combustion, as they are surrounded by a 
thin film of carbolic acid. It is only when collected and this 
acid driven off, that they are consumed. 

It has now been shown that cold is the cause of smoke, 
which may be greatly reduced by care. In the open fire 
grate the existing fire ought to be drawn to the front of the 
grate, and the fresh coal placed behind, or in the back of the 
fire. 'The fire in the front will then burn more rapidly, 
warm the air above, and prepare the raising gases for com- 



i)/ 



Ibustion. In this way smoke is diminished, as the gascs 
from the coals at the back rise much more slowly then when 
placed upon the fire and the air partly warmed. 



WHAT IS LATENT HEAT? 

Heat has its equivalent in mechanical work, and, when 
heat disappears, work of some kind will take its place. 
When a body changes from the liquid to the gaseous form, 
the molecules have to be separated and placed in different 
positions with regard to each other. This calls for an ex- 
penditure of work. This work is supplied by heat, which 
disappears at the time. One can hold his hand in steam es- 
caping from a safety valve of a boiler for this reason. The 
heat of the steam disappears in pushing apart and rearrang- 
ing the molecules of the steam as it expands when it leaves 
the safety valve. 

The term latent heat, as commonly used, means the 
amount of heat which disappears when v/ater changes from a 
liquid into steam. This is considerable, as will be seen by 
consulting any table of the heat contained in steam, and the 
water from which it comes. 

Water at 212° contains 180 units of heat. Steam at 
212^^ contains 1,146 units of heat. The latent heat is the 
difference of 966 uni':s. Such a large quantity disappears 
when liquid water changes to steam, that boiling cannot be 
raised above 212", no matter how hard it is boiled. The 
heat becomes latent, and the mechanical work, or rather 
molecular work, is sufficient to take up all that is supplied by 
the fire. 

The specific heat of air at constant pressure being 
0.2377, the specific heat of water, which is i, is, therefore, 
4.1733 times greater under ordinary circumstances. A 
pound o( water losing i^ of heat, or one thermal unit, will 
consequently raise the temperature of 4.17 pounds, or, at 
ordinary temperatures, say 50' of air, i^. A pound of steam 
at atmospheric pressure, having a temi)erature of 212^ F., 
in condensing to water at 212^^ F., yields 966 thermal units, 
which, if utilized, would raise the temperature of 5X9663 
^,830' of air i^, or about 690' from 5^ to 70'^ F. 



158 
MISTAKES IN DESIGNING BOILERS. 

One of the greatest mistakes that can be made in design- 
ing boilers, and the one that is most frequently made of any, 
consists in putting in a grate too large for the heating sur- 
face of the boiler, so that with a proper rate of combustion 
of the fuel an undue proportion of the heat developed passes 
off through the chimney, the heating surface of the boiler 
being insufficient to permit its transmission to the water. 
This mistake has been so long and so universally made, and 
boiler owners have so often had to run slow fires under their 
boilers to save themselves from bankruptcy, that it has given 
rise to the saying, " Slow combustion is necessary for econ- 
omy." This saying is considered an axiom, and regarded 
with great veneration by many, when the fact is, if the 
truth must be told, it has been brought about by the waste- 
fulness entailed by boiler plants and proportioned badly by 
ignorant boilermakers and ignorant engineers, who ought to 
know better, but don't. 

'Let us consider the matter briefly : Suppose w^e are 
running the boiler at a pressure of 80 lbs. per square inch, 
the temperature of the steam and water inside will be about 
325 degrees F. ; the temperature of the fire in the furnace 
will, under ordinary conditions, be about 2,500 degrees F. 
Now, it should be clear to the dullest comprehension, that 
we can transmit to the water in the boiler only that heat due 
to the difference between the temperature in the furnace and 
that in the boiler. In case of the above figures, about 
seven-eighths of the total heat of combustion is all that 
could, by any possibility, be utilized, and this would require 
that radiation of heat from every source should be absolutely 
prevented, and that the gases should leave the boiler at the 
exact temperature of the steam inside, or 325 degrees. 

To express the matter plainly, we may say that the 
utilization of the effect of 2. fall of temperature of 2.175 
degrees is all that is possible. 

Now, suppose, as one will actually find to be the case in 
many cases if he investigates carefully, that the gases leave 
the flues of another steam boiler at a temperature between 
500 and 600 degrees. The latter temperature will be found 
quite common, as it is considered to give "good draft." 
This is quite true, especially as far as the " draft " on the 
owner's pocket-book is concerned, for he cannot possibly 
utilize under these conditions more than 2,500 — 500=2,000 
degrees of that inevitable difference of temperature to which 
he is confined, or four-fifths of the total, instead of the 



159 

seven-eighths, as shown above, where the boiler was running 
just right, and any attempt to reduce the temperature of the 
escaping gases by means of slower " combustion," as he 
would probably be advised to do by nine out of ten men, 
would simply reduce the temperature of the fire in his fur- 
nace, and the economical result would be about the same. 
His grate is too large to burn coal to the best possible advan- 
tage, and his best remedy is to reduce its size and keep his 
fire as hot as he can. 

This is not speculation, as some maybe inclined to think. 
Direct experiments have been made to settle the question. 
The grate under a certain boiler was tried at different sizes 
with the following result: 

With grate six feet long ratio of grate to heating surface 
was I to 24.4. 

With grate four feet long ratio of grate to heating surface 
was o to 36.6. 

The use of the smaller grate gave, with different fuels and 
all the methods of firing, an average economy of nine per 
cent, above the larger one, and, when compared by burning 
the same amount of coal per hour on each, twelve per cent, 
greater rapidity of evaporation and economy were obtained 
with the smaller grate. 

AVERAGE BREAKING AND CRUSHING STRAINS 
OF IRON AND STEEL. 

Breaking sti^ain of wrought iron =23 tons^ 

Crushing strain of wrought iron =17 tons | 

Breaking strain of cast iron about "]% tons [ Per square inch 

Crushing strain of cast iron =50 tons. ... 1 of section. 

Breaking strain of steel bars about 50 tons | 

Crushing strain of steel bar? up to ii6 tons J 

PITTING OF MQD DRUMS. 

Mud drums have frequently been known to pit through 
their close connection to the brick work with which they 
are covered. When the boiler is filled with cold water, the 
iron will sweat. This moisture mixing with the lime of the 
brick work will, after a length of time, injure the iron. 
Mud drums are injured on the inside by a similar chemical 
action. The sediments of lime, etc., deposit there where 
their action goes on undisturbed by any circulation. To 
prevent pitting on the inside from this cause, blow down fre- 
quently, and, on the outside, keep the brick off the plates, 
so that all moisture can pass off. 



i6o 
TABLE OF SPECIFIC GRAVITIES. 

Weight of a Cubic 
Inch in Lbs. 

Copper, cast 3178 

Iron, cast 263 

Iron, wrought , ^276 

Lead 4103 

Steel 2827 

Sun-metal , •3^77 

DIVISIONS OF DEGREES OF HEAT. 

The thermometer is an instrument for measuring sensible 
heat. It consists of a glass tube of very fine bore, terminat- 
ing in a bulb. This bulb is filled with mercury, and the top 
of the tube is hermetically sealed after all the air has been 
expelled. The instrument is then put into steam arising 
from boiling water; and, when the barometer stands at thirty 
inches, a mark is placed on a scale affixed opposite the place 
the mercury stands at. It is again put in melting ice, and 
the scale again marked. The space between these marks is 
divided into spaces called degrees. In this country and 
England it is divided into 180 equal parts, calling freezmg 
point 32°, so thar the boiling point is 212^ ; and zero or o is 
32^ belowfreezing point, and this scale is called Fahrenheit's. 
On the continent two other scales are in use; the Centi- 
grade, in which the space is divided into 100 equal parts, 
hence the name ; and Reaumur's, in which the space is 
divided into 80. In both of these scales freezing point is o, 
or zero ; so that the boiling point of centigrade is 100^, and 
Reaumur 80°. 

THE LAW OF PROPORTION IN STEAM 
ECONOMY. 

The basis of steam engineering science consists in closely 
adhering to the absolute ratio or proportion of the different 
parts of the steam-plant, representing the power of the en- 
gine and boiler to the amount of the work to be done. To 
use an extreme illustration, it is not scientific to construct a 
hundred horse power boiler — say i ,500 square feet of heating 
surface — to furnish steam for a six-inch cylinder; nor is it in 
proportion to use a cylinder of the latter size to drive a 
sewing machine. It may be said truthfully that the law of 
true proportion between boiler, engine and the desired 
amount of work is less understood than ctlmost any other in 
the range of mechanical practice. 



i6i 

V^ALUABLE INFORMATION FOR ENGINEERS. 

To find the capacity of a cylinder in gallons, multiply the 
area in inches by the length of stroke in inches, and it will 
give the total number of cubic inches ; divide this by 231, 
and you will have the capacity in gallons. 

The U. S. standard gallon measures 231 cubic inches, and 
contains 8;^ pounds of distilled water. 

The mean pressure of the atmosphere is usually estimated 
at 14.7 pounds per square inch. 

The average amount of coal used for steam boilers is 12 
pounds per hour for each square foot of grate. 

The average weight of anthracite coal is 53 pounds to one 
cubic foot of coal ; bituminous, about 48 pounds to the cubic 
foot. 

Locomotives average a consumption of 3,000 gallons of 
water per 100 miles run. 

To determine the circumference of a circle, multiply the 
diameter by3.i4i6. 

To find the pressure in pounds per square inch of a 
column of water, multiply the height of the column in 
feet by .434, approximately, every foot elevation is equal to 
^ pound ]3ressure per square inch, allowing for ordinary 
friction. 

The area of the steam piston, multiplied by the steam 
pressure, gives the total amount of pressure that can be 
exerted. The area of the water piston, multiplied by the 
pressure of water per square inch gives the resistance. A 
margin must be made between the power and tlie resistance 
to move the pistons at the required speed, from 20 to 40 per 
cent., according to speed and other conditions. 

To determine the diameter of a circle, multiply circum- 
ference by .31831. 

Steam at atmospheric pressure flows into a vacuum at the 
rate of about 1550 feet per second, and into the atmosphere 
at the rate of 650 feet per second. 

To determine the area of a circle, multiply the square of 
diameter by .7854. 

A cubic inch of water evaporated under ordinary atmos- 
pheric pressure is converted into one cubic foot of steam 
(approximately). 

By doubling the diameter of a pipe, you will increase its 
capacity four tinier. 

In calculating horse-power of tubular or flue boilers, con- 
sider 15 square feet of heating surface equivalent to one 
nominal horse-power. 



^j2 

HOW TO TEST BOILERS. 

The safe-working pressure of any boiler is found by- 
multiplying twice the thickness of plate by its tensile 
strength in pounds, then divide by diameter of boiler, 
then this result divide by six. This gives safe working 
pressure. 

EXAMPLE. 

Twic^ thickness plate X tensile strength -5- diameter of 
boiler in inches-^6=safe working pressure + one-half more 
= maximum test pressure. 

Diameter of boiler, 60". Thickness of plate, y^". 
Tensile strength of plate, 60,000 lbs. I"x6o,ooo-^6o= 
i,ooo-f-6=i66j^ lbs., which is the safe working pressure + 
83^ lbs. = 250 fbs., which is the maximum test pressure. 

After the safe pressure has been found as above, the 
usual way is to add one-half more for a test pressure, then 
apply by hydraulic pressure as high as the test pressure, and, 
if the boiler goes through this test all right, it is safe to 
run it at two-thirds of test pressure. 

Before putting hydraulic pressure on an old boiler, empty 
the boiler, go over it carefully with the hammer for broken 
braces, weak and corroded spots, figure for safe pressure on 
the thinnest place found in boiler, fill boiler full of cold 
water, and gradually heat it until the desired pressure is 
reached. By this mode of testing by hot water pressure, the 
heated water is expanded, and is more elastic than when cold, 
and is not so liable to strain the boiler. 

Before allowing the pressure to be applied, see that the 
boiler is properly braced and stayed, and that the rivets are 
of proper size. 

All flat surfaces, such as found in fire-box boilers, should 
have stays not over 5 or 6 inches apart, for all ordinary 
pressure and boiler heads not over 7 inches apart. 

On account of the loss of strength in the plates by rivet 
holes, some authorities allow only 70 per cent, of the safe 
pressure given above, for double-riveted boilers, and 56 per 
cent, for single-riveted boilers; 

EXAMPLE. 

166 Tbs. safe pressure in first example x 70 per cent, for 
double-rivets = 116.20 lbs. safe pressure for double-riveted 
boiler. 

166 Tbs. safe pressure in first example X56 per cent, for 
single-riveted seams == 92.96 lbs. safe pressure for single- 
riveted boilers. 



SCALE IN BOILERS 

Mr. T. T. Parker writes as follows to the American 
Machinist : 

If there is one thing more than another that the average 

engineer is careful with, it is the use of boiler compounds. 

With an open exhaust heater and an overworked boiler, and 

using water from a drilled well sixty feet deep in limestone, I 
have had to be rather careful to avoid scale and foaming. 

I offer some notes from my experience under the above 
conditions. 

In using compounds containing sal soda, I had to use 40 
per cent, more cylinder oil, and this invariably reacted, 
through the heater and feed water, on the boiler, and pro- 
duced foaming. I have used six compounds warranted to 
cure foaming with above results. The compounds were 
tannic acid and soda. 

Changing to the use of crude oil, I found that the volatile 
parts went over to the engine, and saved 10 per cent- cylinder 
oil over when using nothing, and 50 per cent, over the use 
of sal soda. There is a peculiar easy manner of making 
steam that is very different from the same boiler using sal 
soda . The results on scale are as follows : 

In changing to a different solvent, the results for a few 
runs were very good, and then it seemed to lose its virtue 
while losing double quantity ; result, foaming. With crude 
oil used continually, I have had scale from one-eighth inch 
thick, but never any thicker, as it came off clean, and was 
very porous. I prefer oil to any acid or alkali solvent. 
For cleaning a scaled boiler I would recommend alternate 
use of oil and sal soda, but the remedy is heroic. If the 
boiler is not clean in two weeks, I miss my guess. I have 
tried kerosene, and found it too volatile to be of value in a 
limestone district. In summing up the results, I believe : 

First — With an open exhaust heater, use only the 
best cylinder oil, which should be at least 80 per cent, 
petroleum. 

Second — If the crude oil does not keep the scale all 
out, alternate one run with sal soda. 

Now, I only offer this as my experience, knowing full 
well that the conditions are never absolutely the same. 
But I know of a plant (in this city) where the boiler is not 
worked up to its full capacity, and which is kept entirely 
free from scale, using hard water, by the alternate use of sal 
soda and crude oil. 



164 
WAGES IN TWO COUNTRIES. 

The poverty and low state of social civilization of the 
Spaniards is indexed quite accurately by their wage rates. 

For instance, the average weekly pay of a bricklayer in 
Spain (Malaga) is $3.80; in the United States $21.18; of a 
mason, $3.30 in Spain, $21.00 in the United States; of a 
carpenter, $3.90 in Spain; $15.25 in the United States; of 
a blacksmith, $3.90 in Spain; $16.02 in the United States; 
of a tinsmith, $3 in Spain, $14.35 i^ ^^^ United States; of 
printers, $4.50 in Spain, $16.42 in the United States; of 
laborers, porters, etc., $2.75 in Spain; $8.88 in the United 
States. While rents and possibly a few native products are 
lower in Spain than in the United States, the difference 
;omes nowhere equaling the wide disparity in wages. 
Moreover in a comparison of this sort the quality of the 
living must be considered as well as the nominal cost. 
Thus lower rents nearly always imply inferior accommoda- 
tions, and, to the average Spaniard, most of the comforts 
and conveniences in ordinary use here are unattainable lux- 
uries. 

That the low rate of Spanish wages does really mean a 
proportionately low consumption and stanc^ard of living, is 
substantiated by one or two significant facts of another 
character; for instance, the per capita annual consumption 
of woolen goods in Spain is only 9 shillings' worth, as 
against 18 shillings in the United States; of sugar, 5 
pounds per annum in Spain, 43 pounds in the United 
States; of beef, 16 pounds per annum in Spain; 62 pounds 
in the United States; of all meats, 49 pounds in Spain; 120 
pounds in the United States; of butter, none in Spain; 16 
pounds in the United States; of coffee, 4 pounds in Spain; 
115 pounds in the United States. 



A NOVEL DYNAMO. 

At the central station of Puteaux, Paris, a novel form 
of dynamo was installed in 1898, which combines the efti- 
ciency of a low-speed engine and the high-tension alternat- 
ing-current dynamo. The engine and dynamo are built 
together, the latter comprising an integral part of the 
engine, as the flywheel is used to carry the field magnets of 
the dynamo. The engine is of the high-speed Corliss type, 
revolving at a speed of 60-120 revolutions per minute. 



I6S 

The armature is fixed, but may be slid out of the magnetic 
field by a lateral movement. It remains motionlesss be- 
tween two sets of magnetic poles and is supported by a 
pillar of cast iron, through which the crank shaft passes. 
The exciting current can be obtained either from a small 
auxiliary dynamo or from a shunt circuit taken from the 
main leads. The current is subsequently reduced by a 
transformer and supplied at a pressure of 200 volts; the 
entire operation showing a high degree of efficiency. 

THE LARGEST ARMATURE. 

The largest armature for the largest generator of elec- 
tricity ever made in the world for a trolley railroad was 
completed in Cleveland, Ohio, in January, 1898, and was 
shipped from the works of the Walker Company for Brook- 
lyn, N. Y. The whole generator, when assembled, is 20 
feet high, 20 feet long and 15 feet wide, or equal in height 
to four ordinary-sized men. It is for the Brooklyn Heights 
Railway Company. The armature, which is the revolving 
part of the generator between the magnets, weighs 90,000 
pounds. It is *j}i feet wide and lo^ feet high. 

WEIGHT OF 1 CUBIC IN. OF VARIOUS METALS. 

Weight in lbs. Weight in ounces. 
Steel, . . . 0.2833 4.533 

Cast iron, . . . 0.263 4.208 

Wrought iron, . . 0.2777 4-444 

Copper. . . . 0.3225 5.159 

Brass, . . . 0.308 5.333 



Coke. — 4 bushels = i sack. 
Petroleum. — i ton^275 galls. 



WEIGHT OF FUELS. 

Coal. — A bushel= 742/^ lbs. 
A sack = 224 " 



AVERAGE WEIGHT OF ANIMALS. 



Cart-horse, 14 cwt. 
Ox, 7 to 8 «« 

Cow, 6>^ to 8 " 

Average weight of a man, 140 lbs. 

A dense crowd of people, 85 lbs. per square foot. 



Riding-horse, ii cwt. 
Pig, I to iy2 '' 

Sheep, I *• 



1^5 

PROPORTIONS OF STEAM BOILERS. 

In a recent communication to the Socieie Scientifique 
Industrielle of Marseilles, M. D. Stapfer remarked that, as 
he had never met with any good practical rules for the pro- 
portions of boilers for steam engines, he had taken the trou- 
ble to examine a very large number of different types, which 
were working satisfactorily, and from them had deduced the 
following rules : The water level in the boilers of torpedo 
boats was usually placed at two-thirds the diameter of the 
shell, and in marine, portable and locomotive boilers at three- 
fourths this diameter. The surface from which evaporation 
took place should, however, be made greater as the steam 
pressure was reduced — -that was to say, as the size of the 
bubbles of steam became greater. To produce lOO Hbs. of 
steam per hour, at atmospheric pressure, this Surface should 
not be less than 7.32 square ft., which may be reduced to 
1.46 square ft. for steam at 75 lbs. pressure, and 0.73 ft. for 
steam at a pressure of 150 lbs. It is for this reason that 
triple-expansion engines can be worked with smaller boilers 
than were required with engines using steam of lower pres- 
sure. The amount of steam space to be permitted depends 
upon the volume of the cylinder and the number of revolu- 
tions made per minute. For ordinary engines it may be 
made a hundred times as great as the average volume of 
steam generated per second. The section through the tubes 
may be one-sixth of the fire-t,"ate area when the draught is 
due to chimney from 27 ft. «. j 33 ft. high, which in general 
corresponds to a fuel consumption of 12.3 pounds of coal 
per square fooc cf grate surface per I:..~»ur. This area may 
be reduced to one-tenth that of the. grate when forced 
draught is employed. 

TESTING BOILER PLATES. 

A good every-day shop plan of testing boiler plates is to cut 
©flf a strip I % inches wide and of any convenient length. 
Drill a quarter-inch hole, and enlarge it to three-quarters of 
an inch by means of a drift -pin and hammer. If the plate 
shows no signs of fracture, it may be considered of good 
quality. 

Another method is to cut oft' a narrow strip, heat it 
to a cherry red and cool suddenly. Grip the piece in a vise, 
and bend it back and forth at right angles by means of a 
piece of gas pipe dropped over the end. The number of 
tim^es the piece can stand this bending is the measure of its 
quah'ty. A good piece of soft steel boiler-plate should stand 
velve or fifteen bendings without showing fracture. 



i67 
MANIPULATION OF NEW ENGINES. 

After engines have been set up, they must be adjusted to 
/heir work. It is not every man that can do this properly, 
for it requires experience and consideration to determine 
exactly what is to be done. A new engine is a raw machine, 
ho to speak, and, no matter how carefully the work has been 
done upon it, it is not in the same condition that it will be 
in a few weeks, or after the actual work it does has worn 
its bearings smooth and true. In the best machine-work, 
there are more or less asperities of surface, and very much 
more friction than than there will be later on. Bearings and 
boxes are not fitted under strain ; they are fitted as they 
stand, independently in the shop, and this entails a condi- 
tion of things which actual work may show to be faulty. 
For this reason an engineer should not go at a new engine 
hammer and tongs, and try to suppress at once every slight 
noise or click that he may hear. Neither should he key up 
solid, or screw down hard, the working shafts and bearings, 
for the first few days. It is much bbtter to let the things 
run easily for a while, at the expense of a little noise, rather 
than to risk cutting before the details get used to each other. 
Many good engines have been disabled by too great zeal on 
the part of those in charge, when a little forbearance would 
have been much better. Pounding, caused by bad adjust- 
meny,^ <Dr valve setting, and pounding caused by new bear- 
ings not in intimate relation with each other, are quite 
different in character, and a careful engineer will not make 
haste to decide upon the remedy until he has indicated and 
investigated the engine, and found out exactly where the 
trouble is. Not long ago we saw a new engine badly cut in 
its guides from this very cause ; a slight jar was noticed, and 
the engineer, arguing that the crosshead was the seat of the 
noise, set out the gibs so much that they seized and plowed 
some bad scores in the cast-iron guides, which will always 
remain to remind him of his thoughtlessness. What has 
been said above of the engine, is also true of the boiler and 
its appurtenances. No new boiler should have pressure put 
upon it at once. Instead, it should be heated up slowly for 
the first day, and whether steam is wanted or not. Long 
before all the joints are made, or the engine ready for steam, 
the boiler should be set, and in working order. A slight fire 
should be made and the water warmed up to about blood 
heat only, and left to stand in that condition and cool off, 
and absolute pressure should proceed by very slow stages. 
Persons who set a boiler and then build a roaring fire under 



1 68 

it, and get steam as soon as they can, need not be surprised 
to find a great many leaks developed ; even if the boiler does 
not actually and visibly leak, an enormous strain is need- 
lessly put upon it w^hich cannot fail to injure it. Of all the 
forces engineers deal with, there are none more tremendous 
than expansion and contraction. 

STATISTICS OF MANUFACTURES IN THE 
UNITED STATES. 

According to the United States census, the number of 
persons engaged in manufactures in the United States in the 
census year v^^as 4,712.622, and earned wages were $2,283,- 
216,529. 

The value of products, including receipts from custom 
work and repairing, was $9,372,437,283; number of estab- 
lishments reporting, 322,638; capital, 6,139,397,785; cost 
of materials used, $5,021,453,326. 

The value of the products of woolen mills in 1890 was 
$I33»577j9775 worsted mills. $79,194,652; carpet mills, 
$47,770,193; hosiery and knitting mills, $67,241,013; cot- 
ton mills, $267,981,724; lumber and timber products, $465,- 
934,244; silk mills, $87,298,454; chemicals, $177,811,833. 

No general statistics of manufactures had been col- 
lected since the 1890 census. The manufacturing industries 
of the United States are covered by the census of 1900. 

STEAM AS A CLEANSING AGENT, 

For cleaning greasy machinery nothing can be found that 
is more useful than steam. A steam hose attached to the 
boiler can be made to do better work in a few minutes than 
any one is able to do in hours of close application. The 
principal advantages of steam are, that it will penetrats 
where an instrument will not enter, and where anything else 
would be ineffectual to accomplish the desired result. 
Journal boxes with oil cellars will get filthy in time, and are 
difficult to clean in the ordinary way ; but, if they can be 
removed, or are in a favorable place, so that steam can be 
used, it is a veritable play work to rid them of any adhering 
eubstance. What is especially satisfactory in the use 01 
Steam, is that it does not add to the filth. Water and oil 
spread the foul matter, and thus make an additional amount 
«af work. 



169 
POINTS FOR ENGINEERS. 

When using a jet condenser, let the engine make three or 
four revohitions before opening the injection valve, and 
then open it gradually, letting the engine make several more 
revolutions before it is opened to the full amount required. 

Open the main stop valve before you start the fires un- 
der the boilers. 

When starting fires, don't forget to close the gauge- 
cocks and safety-valve as soon as steam begins to form. 

An old Turkish towel, cut in two lengthwise, is better 
than cotton waste for cleaning brass work. 

Always connect your steam valves in such a manner that 
the valve closes against tuie constant steam pressuie. 

Turpentine, well mixed with black varnish, makes a good 
coating for iron smoke pipes. 

Ordinary lubricating oils are not suitable for use in pre- 
venting rust. 

You can make a hole through glass by covering it with a 
thin coating of wax — by warming the glass and spreading 
the wax on it, scrape off the wax where you want the hole, 
and drop a little fluoric acid on the spot with a wire. The 
acid will cut a hole through the glass, and you can shape 
the hole Avith a copper wire covered with oil and rotten- 
stone. 

A mixture of one (i) ounce of sulphate of copper, one- 
quarter (X) of an ounce of alum, half (j^) a teaspoonful of 
powdered salt, one (i) gill of vinegar and twenty (20) drops 
of nitric acid will make a hole' in steel that is too hard to 
cut or file easily. Also, if applied to steel and washed ofif 
quickly, it will give the metal a beautiful frosted appear- 
ance. 

It is a fact that thirty-five cubic feet of sea water is equal in 
weight to thirty-six feet of fresh water, the weight being one 
ton (2,240 pounds). 

Remember that coal loses from ten (10) to forty (40) per- 
centum of its evaporative power if exposed to the influenc'" 
of sunshine and rain. 

Those who have had experience think that for lubrical 
ing purposes palm nut oil cannot be surpassed, for the rea- 
son that it does not gum or waste; neither does friction 
remove it readily from the surfaces where it is applied, and 
its use is exceedingly economical. The best cylinder oils 
produce no better effect. 

If you are obliged to make use of such a barbarisn). as a 
rust joint, mix ten (10) parts by weight of iron filings, and 



I70 

three (3) parts of chloride of lime with enough water to 
make a paste. Put the mixture between the pieces to be 
joined, and bolt firmly together. 

Too much bearing surface in a journal is sometimes 
worse than too little. 

Steel hardened in water loses its strength — but hardening 
m oil increases its strength and adds to its toughness. 

PRODUCTION OF COPPER, TIN AND ZINC. 

The production of copper in the world in 1898, stated 
in long tons, was as follows: United States, 239,241; Spain 
and Portugal, 53,225; Chile, 24,850; Japan, 25,175; Ger- 
many, 20,085; Mexico, 15,668; Australasia, 18,000; South 
Africa, 7,060; other countries, 31,025; total, 434,329 tons. 

The copper production of the United States in 1898, in 
pounds, was distributed as follows: Arizona, 110,823,334; 
California, 21,543,229; Colorado, 10,870,869; Michigan, 
156.669,098; Montana, 216,979,334; Utah, 5,385,246; 
Eastern and Southern States, 4.478,218; all others, 2,134, 
999; copper in sulphate (^), 7»oi5»375; total, 535,900,232. 

The production of tin in the world in 1898, in long tons, 
was as follows: England, 5,200; Stmlts Settlements, 45,901 ; 
Australasia, 3,220; Banka, Billiton, and Singkep, 14,380; 
Bolivia, 4,464; Austria {e), 49; Germany [e), 635; Japan 
(^), 39; Mexico (^), 5; Portugal, 70; Russia (e), 5; total, 
73,268. 

The production of zinc in the world in 1898, in metric 
tons, was as follows: Austria, 7,229; Belgium, Holland 
and the Rhine district of Germany, 191,836; Upper Silesia, 
99,232; France and Spain, 32,649; England, 27,625; Rus- 
sia, 5,664; United States, 103,514; total, 467,749. 

AREA OF THE WORLD'S COAL-FIELDS, IN 
SQUARE MILES. 

China and Japan, 200,000; United States, 194,000; 
India, 35,000; Russia, 27,000; Great Britain, 9,000; Ger- 
many, 3,600; France, 1,800; Belgium, Spain and other 
countries, 1,400. Total, 471,800. 

The coal-fields of China, Japan, Great Britain, Germany, 
Russia and India contain apparently 303,000,000,000 tons, 
which is enough for 700 years at present rate of consumption. 

(6) Including only the copper in sulphate obtained as a by-product, 
(e) Estimated. 



71 



MEASURES OF DIFFERENT COUNTRIES 




U3 C^ ;_ QJ 

'«^ II '^ 9^:5 

^« i-i II vo 












f^ 



W5 

On ^ 



C/2 CT* 



^ 



o 

ON 



U l-H 
(U 

.'< 11 

o il 

in cr' 
n CO 



- 00 

SIS 

M C; o 







-^ S 52 
o o s 

0) o id 



METRIC SYSTEM 



0) o 



V S 



S^ 



^ t-1 M 






6 
•4:1 






0) 



^ H B ' ^ ^ ^ 



i * . '^ 

• f=! !rt 5 



5 r-< CA? 



'^tf4t^oo^>i;:z.'^ c;^/^^)^ 






fi tiJL' c« 



^ PI ^ 

CJ !=l M 



0) 



J;^ <U C/} 

rH . On ^ 
d 









■I 



r/2 



THE MONETARY UNITS AND STANDARD COINS 
OF FOREIGN COUNTRIES. 

Tlie first section of the act of March 3, 1873, provides 
* that the value of foreign coin, as expressed in the money of 
account of the United States, shall be that of the pure metal 
of such coin of standard value," and that " the value of the 
standard coins in circulation of the various nations of the 
world, shall be estimated annually by the director of the 
mint, and be proclaimed on the first day of January by the 
secretary of the treasury. 

The estimates of values contained in the following table are 
those made by the director of the mint, Jan. i, 1878. 



Country. 



Argen Repub. 

Austria 

Belgium 

Bolivia 

Brazil 

British Amer . 

Bogota 

Central Amer. 

Chili 

Cuba 

Denmark 

Ecuador 

E-gypt 

France 

Gt. Britain . . . 

Greece 

German Emp . 

India . 

Italy 

Japan 

Liberia 

Mexico 

Neitheriands . 
Norway . c . . . 
Paraguay . . . . 
Peru 



Monetary 
Unit. 



Standard. 



Peso fuerte 

Florin 

Franc 

Dollar 

Milreis of 1 000 

reis 

Dollar 

Peso 

Dollar 

Peso 

Peso 

Crown 

Dollar 

Pound of 100 

piasters .... 

Franc 

Pound sterling 

Drachma 

Mark 

Rupee, 16 an. . 

Lira 

Yen 

Dollar 

Dollar 

Florin 

Crown. , 

Peso 

Sol. 



Gold 

Silver 

Gold & Silver 
Gold & Silver 



Gold. , 
Gold. . 
Gold. , 
Silver . 
Gold. , 
Gold. , 
Gold. , 
Silver, 



Gold 

Gold & Silver 

Gold 

Gold & Silver 

Gold 

Silver 

Gold & Silver 

Gold 

Gold 

Silver , 

Silver 

Gold 

Gold 

Silver ..... 



Value. 



D. c. M. 
100 

o 45 3 
o 19 3 

o 96 5 



o 54 
f. o 
o 96 
o 91 
o 91 
o 92 
o 26 
o 91 

4 97 
o 19 



. 86 
o 19 
o 23 

o 43 
o 19 

99 

1 e 
099 

038 

26 

1 o 

o g6 



i» 



173 



THE MONETARY UNITS — Continued. 



Country. 



Porto Rico. . ., 

Portugal 

Russia 

Sandwich Islands 
Spain 



Sweden . . . , 
Switzerland 

Tripoli 

Tunis 

Turkey . . . . 
Colombia. . , 
Uruguay . . . 



Monetary 
Units. 



Peso 

Mil. looor's . 
Rubles, I GO CO 

Dollar 

Peseta of loo 
centimes . 

Crown 

Franc ■, 

Mah. 2opv's 
Pi's., 26 car. 
Piaster ..... 

Peso , 

Patacon ..... 



Standard. 



Gold. 
Gold. 
Silver , 
Gold. , 



Value. 



sr 



Gold & Sil 

Gold 

Gold & Silver 
Silver. . 
Silver. . 
Gold... 
Silver . . 
Gold... 



092 5 
I 8 o 

o 73 4 
100 



19 
26 

82 
II 
4 
91 
94 



DIMENSIONS OF AMERICAN ENSIGNS, 



Numbers. 


Head or 
hoist. 


Whole 
length. 


Length ot 
union. 




Feet. 


Feet. 


Feet. 


I 


19.00 


36.00 


14.40 


2 


16.90 


32.001 


12.80 


3 


14.80 


28.00 


11.20 


4 


13.20 


25,00 


10.00 


r. 


11.60 


22.00 


8,80 


5 


10.00 


19.00 


7.60 


1 


«.45 


16 00 


It 


7-40 


14.00 


Q 


33 


12.00 


4.80 


ic 


5.28 


10.00 


4.00 


ti 


4.20 


8.00 


3.20 


£2 


3.70 


7.00 


2.80 


13 


3.20 


6.00 


2.40 


14 


2.50 


5.00 


2.00 



TO DETECT IRON FROM STEEL TOOLS. 
It is diffiult to distinguish between iron and steel tools. 
They have the same polish and workmanship ; use will com- 
monly show the difference. To make the distinction quickly, 
place the tool upon a stone, and drop upon it some diluted nitric 
acid, four parts of water to one of acid. If the tool remains 
clean, it is of iron; if of steel, it will show a black spot where 
touched with the acid. These spots can be easily rubbed oE 



174 
ARTIFICIAL ICE-MAKING, 

Reduced to the fewest words, the scientific principle under- 
iying all methods for making artificial ice is that whenever 
a liquid is evaporated it takes up more or less heat from sur- 
rounding objects. This fact can be easily demonstrated by 
any one. Stick your finger in your mouth and moisten it 
with saliva. Then hold the wet finger in the wind. At once 
that finger feels colder than the rest, for the moving air 
takes up or evaporates the moisture, and the skin gives up 




some of its heat. It is an old scientific trick to freeze water 
in a fire by wrapping the bottle with a rag soaked in ether or 
chloroform. The heat of the fire evaporates the highly vola- 
tile ether so quickly that the ether sucks all of the heat out 
of the water and freezes it. This is practically what the ice 
maker does, only he uses ammonia or sulphurous oxide in- 
stead of ether, and works on a large scale with large pumps, 
engines and miles of iron pipe. 



175 

At ordinary temperature, ammonia is a vapor or gas. The 
common ammonia sold in drug stores is really ammonia 
water made by saturating water with ammonia gas. The 
Ammonia commonly used in ice-making is anhydrous am- 
monia, which is liquid ammonia without any water in it. 
There are many kinds of ice-making machines made, but all 
practically work on the same principle. 

The principal part of the plant is the compressor pump. 
Then follows the condenser, the expansion coils and the re- 
ceiver. The anhydrous ammonia is received by the ice- 
maker in oblong iron drums containing 100 pounds or more, 
and it is fed into the pump through a small pipe to the suc- 
tion valve at the lower end of the pump, whether it be single 
or double acting. The pump performs a double office, for 
with one stroke of the piston it sucks in the anhydrous am- 
monia, and on the return stroke compresses the gas to a 
liquid, for the anhydrous ammonia is used over and over 
again, first as liquid, then as an expanding gas freezing the 
liquid, and then back as a liquid again. The ammonia gas 
is liquified not only by pressure but by cold. The pump 
forces the gas into the condenser first. This is a series of 
coils of small pipe over which cold water is constantly fiow- 
ing. The gas pressed into the smaller pipes is condensed to 
liquid ammonia. As it condenses, the liquid ammonia fiows 
into a storage tank through small pipes leading from the 
condenser. The pressure from the pump and suitable check 
valves force the liquid ammonia from the storage tank, 
which lies in a horizontal position, into two large vertical 
cylinders, and from them into the expansion coils which lie 
in the bottom of the freezing tanks. 

Tht) pipes of the expansion coil are much larger than the 
pipes in the condenser, and here the liquid ammonia expands 
or turns to vapor again, and as it evaporates it takes the 
heat from the salt brine in the tank and reduces its tempera- 
ture from 18 o above to 10 o below zero, depending on the 
fiow of the gas. The compressor pump, by forcing the liquid 
ammonia from it and sucking the gas towards it, keeps the 
anhydrous ammonia moving along constantly, and it goes 
into the receiver, from which it is pumped to be compressed 
and chilled into a liquid again. 

The ice factories which use sulphurous oxide instead of 
anhydrous ammonia have a brine made from magnesium 
chloride instead of common salt, but in other respects the 



170 

system is about t:ie same. The anhydrous ammonia and 
sulphurous oxide processes are called the compression 
system. In the absorption system the liquid is first heated 
in a boiler and the vapor which is generated is made up of 
about 9 parts of ammonia gas and 1 part of steam. This 
vapor first passes through a condenser, where the steam is 
tui'ned into water again, but as the temperature is not low 
enough to liquify the ammonia gas, it is forced along by the 
boiler pressure to another condenser. Here the gas is con- 
densed to a liquid, and then passes on to the expansion coils 
just as it does in the compression system. After doing its 
work, the gas is brought back to the "absorber," where it is 
taken up by water again and pumped back into the boiler. 

In making artificial ice, the manufacturer wants pure 
water. To be certain that the water is free from sediment 
and typhoid germs, he filters and distils the water before it 
is frozen. In some ice works the water is filtered once before 
it is distilled, and twice afterwards. The freezing tanks are 
made of iron. , They usually are set below the floor for the 
purpose of facilitating the handling of ice. The average 
tank is about 50 feet long, 20 feet wide and 4 feet deep. The 
cans in which the distilled water is frozen are 44 inches by 
22 inches by 11 inches in size. 

The pipes which carry the anhydrous ammonia go back 
and forth across the tank between the ams, and the salt 
water brine is kept in motion by an agitator something like 
a screw propeller. This gives the brine an even tempera- 
ture. It requires from 34 to 60 hours to freeze a 300- pound 
cake of ice. Over the freezing tank is a traveling crane with 
a block and tackle for hoisting the cans with the frozen 
blocks out of the tank. The cans are lifted, so that when 
clear of the tank they tilt upside down. Streams of tepid 
water are directed on the can, and in a short time the cake 
of ice slips out of the can and slides down the gangway to 
the ice-house. 

Nearly every brewery in the country has its own refriger- 
ating plant. For cooling cellars, vaults and other parts of 
the brewery, chilled brine is pumped througn pipes. Some- 
times, howevv.r, as in the direct expansion method, the ex- 
pansion pipes are used. Both methods are also employed in 
chemical works, cold storage warehouses and packing 
houses. Ice machines are rated with capacities varying from 
50 to 100 tons of ice a day. They are built vertical and hori- 



177 

zontal, single and duplicate, operated either direct or from 
an engine. 

NOVEL USES OF COMPRESSED AIR. 

Most people think that compressed air is only used for 
automatic car-brakes and rock drills. The fact is, com- 
pressed air as an agent for transmitting energy and power 
is pushing electricity liard and, on some lines, has distanced 
steam. 

On many railroads compressed air has taken the place of 
whisk brooms and beaters for cleaning seat cushions of pas- 
senger cars. The air at 50 to 75 pounds pressure to the 
square inch is brought into the car through an air hose 
which has a brass air nozzle on the end. The women handle 
this nozzle as though water instead of compressed air were 
coming through, and the air jet drives the dust, cinders and 
dirt out of the cushions quicker and better than any other 
method. 

In the new criminal court building of Chicago, a system ol 
pneumatic clocks has been installed. The "master" clock 
sends pulsations of compressed air through small pipes to 
the connecting clocks, and thus all run on the same time an<^ 
are regulated together. 

In several machine shops in the country there is not a belt 
or a piece of shafting outside of the engine-room. Instead, 
pipes run from the compressed air reservoir to compressed 
air motors. Each drill, lathe, reamer, milling machine, 
emery wheel, bending rolls, punch, drop hammer and press 
has its individual air motor or engine, and the mere turning 
of a throttle valve starts or stops the machine. 

The pneumatic clock system was installed first in Paris 
about 1870. From it grew the present compressed air cen- 
tral-pov/er system, which supplies over 10,000 horse-power 
to users in the French capital. It is there used for all pur- 
poses, from running clocks to operating dynamos for elec- 
tric lights. The central station furnishes air at a pressure 
of 75 pounds to the square inch. 

Asphalt used for street-paving is refined by compressed air. 
In its original shape, just as it comes from Trinidad, asphalt 
is too soft for street-paving, and is not homogeneous To 
refine it, the asphalt is boiled in kettles for three or four 
days, and while r.^^ heat is on it must be stirred. Pipes hav- 



.i78 

ing numerous holes are placed in the bottom of the kettle, 
and while the asphalt is boiling, compressed air is forced 
through the pipes and, escaping through the holes, agitates 
the thick black material, thus refining it. 

Compressed air was the paint-brush which placed the color 
on the World's Fair buildings in Chicago, and which to-day 
is painting railroad bridges and corrugated iron plates for 
buildings. The compressed air not only draws the liquid 
paint from the tubs or buckets, but sprays it over the sur- 
face and drives it into the wood. 

In the big shipyards, where the government vessels are 
built, all the calking is done by compressed air, and one com- 
pressed air calking machine does the work of four men. 
This calker strikes 1,000 blows a minute. The same tool is 
used by boiler-makers, and, in a modified form, by stone- 
cutters for dressing and carving stone. The little engine 
which does the work is in the handle of the tool which is 
about the size of a large chisel handle. The air is brought 
to the tool by a small rubber pipe, which is so flexible it can 
be handled easil:^ and at any angle. A piston and spring 
shove the tool in and out, and it can be so adjusted that the 
heaviest or mosb delicate work can be done with it. 

Acids which would eat a pump up at once, are raised by 
compressed air. Sewage which is below the level of the 
sewer is forced up by compressea air. Impure water is 
cleaned, gold and silver are dug from mines, letters are 
copied m the letter press, elevator signal bells are rung, 
cattle are lifted after being killed in slaughter houses, fur- 
nace grr.tes are shaken, crude oil is atomized under steam 
boilers, grain is cleaned, and a hundred other things are 
daily done by compressed air. 

CONCEKNING ELECTKIG BATTEEIES. 

In a general way batteries are divided into two classes- 
open circuit batteries and closed circuit batteries. In all 
kinds of batteries the electro-motive force decreases and the 
internal resistance increases when working on a circuit of 
low resistance. This is caused by "polarization," which is 
the collecting of tiny bubbles of hydrogen gas on the nega- 
tive plate due to the action of the current. These bubbles 
covering the negative plate not only diminish the working 
smrface cf the plate, and thus reduces the electro-motive 



179 

force, lou.^ increases the resistance. In this condition the 
battery is said to he polarized. To correct this evil various 
chemicals, either fluid or solid are placed in the battery to 
generate oxygen which may unite with the hydrogen. Such 
chemicals are called "depolarizers.'' Those batteries in 
which the depolarizers act slowly and after the battery has 
stopped work are called "open circuit"; that in which the 
depolarizers is working is "closed circuit." The open circuit 
battery is used where the demand for the current is inter- 
mittant; the "closed circuit battery" is used where the cur- 
rent is required almost continuously. 

Batteries should be kept where the temperature is about, 
even, avoiding extremes of heat or cold. They should be 
carefully protected from dust and dirt. The cells should be 
covered so as to prevent rapid evaporation of the solution. 
The best place for batteries is a dry cool place. 

Where zinc is used in a battery the plate should be rolled 
and not cast zinc. The carbon plates should be solid, fine 
and hard. Those made from gas-retort carbon. The upper 
part of carbon rods should be dipped in melted paraffline 
until the wax has soaked in, say to an inch or so from the 
top. This will keep the solution from "creeping" or crawl- 
ing up, as it will do unless the rod is waxed. Before a zinc 
rod is placed in a battery it should first be thoroughly 
brightened by scouring it with weak sulphuric acid, and then 
a small portion of mercury should be rubbed over it. The 
amalgamation will prevent what is known as "local action." 
Sal-ammoniac, if used, should be pure, otherwise the battery 
will become dirty. Porus cups should be soaked in water 
and then thoroughly scrubbed out. Carbon plates, in renew- 
ing batteries, should be treated in the same way. Batteries 
should never be neglected if good work from them is desired. 
A poor battery is often worse than no battery at all, and it is 
false economy to re-charge with impure and therefore cheap 
chemicals. 

HOW BOILEK PLATES AKE PROVED. 

This is done by placing a piece of Bessmer steel 10 inches 
long in a testing machine. Gradually the surface scales off 
in the middle, to become smaller in area, and somewhat 
elongated, til, at last, it breaks with a sharp snap at a break- 
ing strain of about 28 tons to the square inch, the reducticm 
of area being 51 per cent, and the elongation 23 per cent. ? 



i8o 

DIFFERENCES OF TIME FROM NEW YORK. 
At any Giveit Time in New York it is in — 

HRS. MIN. SEC. 

Amsterdam (Holland) 5 16 later, 

Berne (Switzerland) 5 26 " 

Berlin ( Prussia) 5 49 35 " 

Brussels (Belgium) 5 13 30 " 

BTidaPesth( Hungary) 6 12 

Carlsruhe (Baden) 5 30 

^hristiania (Norway) 5 39 

Cologne (Germany) 5 24 

Constantinople (Turkey) 6 52 

Copenhagen (Denmark) 5 46 " 

Dublin (Ireland) c 4 30 30 " 

Frankfort (Germany) 5 30 

Geneva (Switzerland) 5 20 30 

Gothenburg (Sweden) _ 5 45 

Greenwich (England) 4 56 

Hamburg (Germany). . , 5 36 

Lisbon (Portugal) , 4 19 30 " 

London (England) ^ 4 55 56 " 

Madrid (Spain) 4 4. 15 " 

Moscow (Russia) 7 26 " 

Munich (Bavaria) 5 42 30 " 

Naples (Italy) 5 53 " 

Paris (France) 5 05 15 " 

Prague (Austria) 5 54 

Rome (Italy) 5 46 

St. Petersburg ( Russia) 6 57 

Stuttgart (Wiirtemberg) . , . .' 5 33 

Stockholm (Sweden) 6 08 

Trieste (Austria) 5 51 

Venice (Italy) 5 45 30 ' 

Vienna (Austria 6 01 33 ^* 

Warsaw (Poland) 6 20 ** 

The differences are at the rate of one hoar for e^":r7 
fifteen degrees of longitude, or four minutes for each degree* 

A VALUABLE PRESERVATIVE PAINT. 

Soapstone incorporated with oil, after the manner of pamt, 
is said to be superior to any kind of a paint as a preservative. 
Soapstone is to be had in an exceedingly f ne powder, mixes 
readily with prepared oi^s for paint, which covers well surfaces 
of iron, steel, or stone, and is an effectual remedy against 
rust. 



<( 



(( 



i8i 



TIME AT DIFFERENT PLACES, WHEN IT IS 12 

O'CLOCK AT NEW YORK CITY; ALSO, DIE- 

FERENCE IN TIME FROM NEW YORK. 



New York City 12 M. 



Places. 



Albany, N. Y 

Annapolis, Md 

Augusta, Me 

Baltimore, Md 

Bangor, Me 

Boston Mass 

Buffalo, N. Y 

Charleston, S. C 

Chicago, 111 

Cincinnati, O 

Cleveland, O 

Columbus, O. * . . . . , 

Concord, N. H 

Detroit, Mich. 

Eastport, Me , 

Fall River, Mass 

Frankfort, Ky , 

Halifax, N. S 

Harrisburg, Pa , 

Hartford, Conn. . , . . 

Key Wej':, Fla. 

Leavenworth, Kan . , 

Lexington, Ky 

Liverpool, Eng.. , . . , 
Louisville, Ky.. , . , 

Lowell^ ilass 

Memphis, Tenn 

Milwaukee, Wis. ... . 

Montpelier, Vt , 

Montreal, Que 

New Orleans, La ... , 
Niagara Falls, N. Y, 

Norfolk, Va 

Omaha, Neb , . 



II M S 



50 
16 

49 
20 

II 

40 
36 

5 

18 
28 

23 
10 
23 
28 
II 
17 
41 
48 

5 
28 

37 
18 

43 



.|P.m 

4, a.m. 

40 p.m 

33 a.m. 

p.m 

a 



ii|i4 
12 10 

1055 

II 

12 

12 

10 

II 

II 

10 



a.m. 



(( 

p.m 
a.m. 
p.m 

u 

a.m. 

p.m 
a.m. 

p.m 



50 a.m. 
4 a. m. 
48 " 



p.m 
a.m. 
p.m 
a.m. 



a.m. 



Fast. Slow. 



H 



4 43 
10 



36 
48 



H 



MS 



56 

27 



40 

42 

31 

58 

24 
12 

10 



4240 
II 20 



10 
12 



37 



4 
20 16 

9 14 

27 5^ 



I82 

TIME AT DIFFERENT PLACES.— Continuea. 



New York City 12 M. 



Places. 



Qswego, N. Y 

Iris, France 

r^iladelphia, Pa 

Pike's Peak, Col. .... 

Pittsburg, Pa 

Portland, Me 

Providence, R. I. . . . 

Quebec, Que 

Raleigh, N. C 

Richmond, Va. . . . . . 

Sacramento, Cal 

Salt Lake City, Utah 
San Francisco, Cal. . 

Savannah, Ga 

Springfield, Mass. . . 

St. Louis, Mo 

Syracuse, N. Y 

Toronto, Ont 

Trenton, N. J 

Washington, D. C... 



H 



M 



49 
5 

55 
56 
35 
15 
10 
II 
40 
46 

50 

27 
46 

31 

5 

54 
51 

38 
57 
47 



36 
21 
20 

52 
2 

25 
II 

48 
10 

9 
36 
13 

39 

37 

59 
12 

27 

24 

48 



p.m 
a.m. 



p.m 



a.m. 



p.m 
a m 



Fast. 



H 



M 



21 



Slow^. 



H 



M 



24 

40 

8 



12 
50 
51 

24 

47 
21 

I 

48 

33 
36 
12 



^-ENGTH AND 



NUMBER OF TACKS TO THE 
POUND. 



Title. 


Length. 


No. p. lb. 


Title. 


Length. 


No. p. lb. 


I oz. 


yi in. 


16,000 


10 oz. 


II-16 


1,600 


iy2 " 


3-16 - 


10,666 


12 *' 


^ ■ 


1.333 


2 " 


Ya '' 


8,000 


14 *' 


13-16 


1. 143 


2K " 


5-16 - 


6,400 


16 '* 


rs 


1,000 


6 " 


Vz ** 


5.333 


18 ** 


15-16 


888 


4 " 


7-16 - 


4,000 


20 *' 


I 


800 


6 " 


9-16 ** 


2,666 


22 " 


11-16 


727 


8 « 


H " 


2,000 


24 ** 


i>^ 


666 



i83 

SWITCHING FROM THE ENGINE CAB. 

A device that will enable the engineer, from his cab, to 
switch his locomotive at pleasure, while the conductor on 
the caboose or rear car closes the switch again, would surely 
be a novelty in railroading, amounting to a revolution. Yet 
a Cleveland inventor claims to have solved the problem, and 
to be able to demonstrate its practicability with a working 
model. Not to go into the details, it may be sufficient to 
say that the " central throw " switch is shifted by a double- 
flanged shoe, of any length, dropped from beneath any front 
or rear truck, while the train is in motion, first overthrowing 
the crank that draws the lock-plate off the fixed rail, then 
moving the lug of the angle connected with the fly-rail to the 
right or left, as indicated by the target on the engine or 
caboose, after which the lock slides forward and grasps the 
fixed rail, holding the " fly " in alignment, making a continuous 
rail. Thus, a switch is carelessly left open, ar,d a passenger 
train is approaching. The engineer detects the danger ; the 
improvised " shoe" is dropped to the rail ; it strikes the lug, 
the switch is closed, and, a collision avoided. On the other 
hand, a train may be side-tracked by the same simple 
operation from the cab. Of course, this would do away with 
switchmen and frog accidents, and a great many other disad- 
vantages incident to the present method, should the invention 
come into practical use. This, aiecessarily is yet to be dem- 
onstrated by actual test, under varying conditions, before 
success can be confidently claimed ; but the device is certainly 
of general interest. 

ELECTRIC LIGHTING. 

In an address before the Montauk Club of Brooklyn, 
Mr. Charles W. Price stated that over $600,000,000 had 
been invested in electric lighting in the United States; and 
that the total horse power required in the electric lighting 
of Greater New York was not less than 200,000 horse 
power; that in the last thirteen years since the birth of 
the electric railway there had been an expenditure of more 
than $1,700,000,000, and that now any one could travel by 
electric cars from Paterson, N. J., via New York, to Port- 
land, Maine, with only three insignificant interruptions 
which collectively amount to less than fifteen miles. 

Between Chicago and Milwaukee, a distance of 85 
miles, a series of trolley lines connect th*^ two cities by 
electric cars. 



i84 

MANILLA ROPE TRANSMISSION, ^ 

A four-strand, hard-laid manilla rope, having a core, or 
"heart-yarn," is probably the best rope for transmission pur- 
poses, although three-strand rope is generally recommended, 
says a writer in the Ainerican Miller. Of course it is im- 
portant to have the rope laid in tallow, as that greatly pro- 
longs its life. The matter of splice is also important. Sea- 
men all agree that the long splice is the best, but the expe- 
rience of rope-transmission men is almost universally in 
favor of a short splice. The length of a long splice in an 
inch diameter rope will be five or six feet, while a short one 
is two and two and a half feet. I think this is what the 
sailors term "a short splice." I have seen a short splice suc- 
ceed where long ones have repeatedly failed. I have known 
of a manilla rope used out of doors being painted with oil, 
and then varnished. It seenjs to w^ork well. Tar is certainly 
unsuitable as a dressing for transmission rope. In the first 
place it weakens it; in the second, its sticking to the pulley 
or sheave would be a detriment rather than an improvement. 
There is no difficulty about the ropes sticking on rhe sheave, 
if properly designed and constructed. 

SAFE WORKING PRESSURE FURNACE FLUES. 

In a report to his company, the chief engineer of the 
Engine, Boiler and Employers' Liability Insurance Company, 
purposes the following rule for the safe-working pressure for 
cylindrical furnaces in flues : Safe-working pressure 

50/2 d 



where 

/^thickness of plate in thirty-second of an inch. 
i=length of flue in feet. 
^/=diameter in inches. 

RIVETLESS STEEL SLEEPERS. 
Mr. H. Hipkins has invented a rivetless steel sleeper fot 
railroads. The lips or jaws for holding the rails in place are 
stamped out of the solid plate, and are stiffened by corruga- 
tions or brackets, which are also raised from the solid plate 
out of the hollow at the back of each jaw. A center strip 
is provided for the rail to rest upon, dispensing with all rivets 
and loose parts. These sleepers can be laid rapidly, and they 
are claimed ^o be especially adapted to use underground in 
mires 



185 

TAKE CARE OF YOUR AUTOMATIC SPRINK- 

LERS. 

Many business blocks, workshops, Stores, etc., have been 

expensively fitted up with automatic sprinklers as a safeguard 
against fires, a certain temperature of heat fusing the metal, 
opening a valve and letting on a flow of water. But an in- 
spection of the perforated pipes in a majority of instances will 
reveal the fact that the apparatus has been neglected. Cob- 
webs and dust cover the pipes, the sprinklers have been per- 
mitted to corrode and unsolder, and, should a fire chance to 
occur and the friendly services of the sprinklers ever be 
required, they would be found almost useless, and for all the 
work they would perform in the line of throwing cold water 
on the devouring elements, the premises might as well have 
remained "unprotected." 

HOW TO OVERCOME VIBRATION. 

How to put the smith shop in an upper story \vithout 
having the working on the anvils jar the building, has been a 
problem that has frequently given manufacturers trouble. A 
mechanical engineer says it may be safely done by placing a 
good heavy foundation of sheet lead on the floor, and on that 
putting a good 'hickness of rubber belting. 

Another person who is interested in the problem has tried 
the experiment, with some success, of placing the block, not 
on the floor, but on the joist direct, making a cement floor up 
to the block, and over the wooden floor, reaching back beyond 
the reach of sp3rks. It is sometimes said thaE blacksmith 
shops never burn, but they keep right on burning in spite of 
theory, and cement floors ought to be helpful in guarding 
airainst fires. 



SAWMILL OPERATED BY AIR. 

The only sawmill in the world where the machiney is 
operated by compressed air is located in Oronto, Me., and 
the water wheel and the air compressor are below the floor 
of the mill, with also large storage tanks. Pipes lead the 
air to the various machines, whic^ technically are known as 
the carriage, nigger, log-leade^*. !c'2"flipP^^» band log-saw 
and two cut-off saws. *'• 



i86 
ALLOYS AND SOLDERS. 



ALLOYS. 




<v 

a. 
a. 

U 

112 

100 

160 

2 

32 
16 

I 

64 


X 
15 

5 


§ 

s 

< 


<u 


1 

a 

P4 


Brass engine bearings 

Tough brass, engine work. . . . 

" for heavy bearings 

Yellow brass, for turning 


13 
15 

25 


























Flanges to stand brazing 







I 




Bell metal 


5 
10 




Babbitt's metal 




I 






Brass locomotive bearings. . . . 
" for straps and glands . . . 

Muntz's sheathing 

Metal to expand in cooling. . . 


















2 
17 


9 




Pewter •• ...• 


100 








Spelter 


I 

90 








Statuary bronze 


2 


I 
I 


2i 


Type metal from 


3 

7 

2 

I 


• • * # 


« to 


• . • • 

I 
I 
2 




. . . . 




SOLDERS. 

For lead 




« tin , 










" pewter 










" brazing (hardest) 


3 

I 

4 


3 






« " (hard) 










" « (soft) 


I 
2 








(C a a 


I 


.... 


• • • • 



HOW TO MAKE HARD AND DUCTILE BRASS 
CASTINGS. 

Two per cent, by weight of finely pounded bottle glass, 
placed at the bottom of the crucible in which red brass is. 
being melted for castings, gives great hardness, and at the 
same time ductility to the metal. Porous castings are said to 
be almost an impossibility when this is done, and the product 
is likely to *^e of great service in parts of machinery subject to 
strain. A.n addition of one per cent, of oxide of manganese 
facilitates working in the lathe and elsewhere where great 
hardness might be an objection. 



18; 

DECIMAL EQUIVALENTS 

of 8ths, i6ths, 32ds and 64ths of an 



Inch. 



Fractions Decimals 


Fractions Decimals 


of an of an 


of an of an 


Inch. Inch. 


Inch. Inch. 


1-64 = .015625 


33-64 =.5 15625 


1-32 = .03125 


17-3 =.53125 


3-64= .046875 


35-64 = .546875 


1-16 = .0625 


9-16 = .5625 


5-64 == .078125 


37-64 =-578125 


3-32 = .09375 


19-32 = .59375 


7-64= -109375 


39-64 = .609375 


Vs =-i25 


ys = .625 


9-64 = .140625 


41-64= .640625 


5-32 = .15625 


21-32 = .65625 


11-64= .171875 


43-64= .671875 


3.16= .1875 


11-16 = .6875 


13.64= .203125 


45-64=. -703125 


7.32 = .21875 


23-32 = .7185 


15-64 = .234375 


47-64 =.734375 


X = .25 


^ = .75 


17-64 = .265625 


49-64 =.765625 


9^32 = .28125 


25-32 = .78125 


19-64 = .296875 


5 1.64 =.796875 


5-16 =.3125 


13.16= .8125 


21-64 =.328125 


53-64 = .828125 


11-32 = .34375 


27-32 = .84375 


23-64 = .359375 


55-64 =.859375 


H = -375 


rs = .875 


25-64= .390625 


57.64 = .89625 


13-32 = .40625 


29-32 = .90625 


27-64 = .421895 


59-64 = .92i87v, 


7-16 = .4375 


15-16 = .9375 


29-64= .453125 


61-64 = .953125 


15-32 = .46875 


31.32= .96875 


31-64= .484375 


63-64 == .984375 


>^ = .5 





HOW TO ANNEAL SMALL TOOLS. 
A very good way to anneal a small piece of tool steel is to 
Aeat it up in a forge as slowly as possible, and then take two 
fireboards and lay the hot steel between them and screw them 
in a vice. As the steel is hot, it sinks into the pieces of 
wood, and is firmly imbedded in an almost air-tight charcoaj 
bed, and when taken out cold will be found to be nice and 
soft. To repeat this will make it as soft as could be wished. 



AN EXPERIMENT WITH A f.OCOMOTIVE. 

A locomotive engineer who takes an intelligent interest 
m operating his engine economically, relates the particulars 
of runs where careful efforts were made to test the differ- 
ence in the consumption of coal that resulted with the re- 
verse lever hooked back as far as practicable and the throttle 
full open, and running with a late cut-off, and the steam 
throttled, or the difference between throttling and cu'ttingoff 
short. 

First Case — A train of 19 loaded and 12 empty cars, 
rated at 25 loads. Run from Mansfield to Lodge, distance, 
8.6miles, nearly level. Forced the train into speed, and then 
pulled the reverse lever to the center notch, and opened the 
throttle wide. The engine jarred a good deal, due, doubtless, 
to the excessive compression, but the speed was maintained. 
Twenty-two minutes were occupied by the run, a speed of 
23 miles per hour, and 17 shovelfuls of coal were con- 
sumed in keeping up steam. By weighing, it was found a 
shovelful averaged 14 pounds, making the coal used per 
train mile average 27.7 pounds. 

Second Case — A train of 25 loads and six empties, rated 
as 28 loaded cars. Ran, as in the first case, from Mansfield 
to Lodge. Pulled the train into speed in as nearly as possi- 
ble the same time as in the previous test, but, when the 
speed was attained, kept the reverse lever in the nine-inch 
notch, and throttled the steam to keep down the speed. 
Although the train was rated two loads heavier than the pre- 
vious one, it consisted mostly of merchandise, while the 
other vvas heavy freight, and handled decidedly easier. Hav- 
ing pulled both trains over 40 miles before arriving at Mans- 
field, there was full means of judging which was the easier 
train to handle. 

The run was made in 24 minutes, two minutes longer 
than in the other case, and 32 shovelfuls of coal were used, 
being at the rate of 52 pounds per train mile. In both 
'nstances the fire was as nearly as possible the same depth at 
the beginning and end of the run. 

Our correspondent thus concludes his narrative: " It is 
interesting to know that on the first occasion 238 pounds of 
coal were used to do the same work in less time than 448 
pounds were required to do under the changed circumstances 
of the second trip; showing that a gain of 88 per cent, may 
be effected by running with full throttle and early cut off.'^ 



i89 

THE MORSE CODE. 

As all moto-vehicles must be furnished with a sound- 
producing instrument, either a whistle, horn or bell, as well 
as with lamps, automobilists are readily enabled by the 
Morse code to signal or send a message, either by sound or 
by flashing signals, a considerable distance. Apart from 
this, a knowledge of the Morse is invaluable to the trav- 
eller, soldier, and seaman. 

A 

C 

E - 

H 

I -- 



J - «- ^ ^ 


s <• * * 


K -i- - — 


T — 


L - — > - • 


U 


M 


y • . • -■ 


N 


W 


— ^ — 


X — - - — 


p • .. «- •• 


Y — -• — •^ 


Q -i^ ... - — 


Z «>• — - -• 


R 




Numerals, 




4 


7 


5 


8 






6 


9 


.. • . • • 


■M mm i^ mm • 








B 2 

LIQUID FUEL BURNERS. 

These are mainly of two distinct types: gasifiers and 
sprayers. In the former the fuel, usually a heavy liquid 
hydrocarbon, flows into a chamber called a vaporiser, upon 
which impinges a flame. The liquid is converted into a 
liquid vapor or gas which burns in the free p.iesence of air 
with a yellow flame, or it can be mixed with air as in a 
Bunsen burner, when a blue flame is produced. 

A WARNING TO ENGINEERS. 

Never take the cap off a bearing and remove the upp^r 
brass to see if things are working well, for you never can 
replace the brass exactly in its former position, and you will 
find that the bearing will heat soon afterward, on account 
of your unnecessary interference. If there is any trouble, 
you will find it out soon enough. 



190 

WEIGHT AND AREAS OF 

SQUARE & ROUND BARS OF WROUGHT IRON 

And Circumference of Round Bars. 

One cubic foot weighing 480 lbs. 



Thickness 


Veigbl <Jf 


Weight of 


Area of 


1 

Am of 


Cireumferen« 


r Diameter 


□ Bar 


Bat 


□ Bar 


Bar 


of Bw 


in laches. 


One Foot long. 

.013 


One Foot long 


l!l sq. inches. 


m sq. inches. 


in inches. 


J 


.010 


,0039 


.0031 


.1963 


i 


.052 


.041 


.0156 


.0123 


.3927 


i^ 


.117 


.092 


.0352 


.0276 


.58190 


\ 


.208 


.164 


.0625 


.0491 


.7864 


I 


.326 


.256 


.0977 


.0767 


.9817 


1 


.469 


.368 


.1406 


.1104 


1.1781 


I 


.638 


.601 


.1914 


.1503 


1.3744 


h 


:833 


.654 


.2500 


.1963 


1.5708 


/c 


1.055 


.828 


.3164 


.2485 


1.7671 


f 


1.302 


1.023 


.3906 


.3068 


1.9635 


H 


1.576 


1.237 


.4727 


.3712 


2 1598 


1 


1.875 


1.473 


.5625 


.4418 


2 3662 


if 


2.201 


1.728 


.6602 


.5185 


2.5525 


1 


2.552 


2.004 


.7656 


.6013 


2.7489 


A 


2.930 


2.301 


.8789 


.6903 


2.9452 


1 


3.333 


2.618 


1.0000 


.7854 


3.1416 


t'.; 


3.763 


2.955 


1.1289 


.8866 


3.3379 


V 


4.219 


3.313 


1.2656 


.9940 


3 5343 


h 


4.701 


3.692 


1.4102 


1 1075 


3.7306 


# 

il 


5.208 


4.091 


1.5625 


1.2272 


3.9270 


5.742 


4.510 


1 7227 


1 3530 


4 1233 


i 


6.302 


4.950 


1.8906 


1 4849 


43197 


I 


6.888 


6.410 


3^0064 


1.6230 


4.5160 


i 


7.500 


5.890 


2.2500 


1 7671 


4 7124 


/; 


8.138 


6.392 


2.4414 


1.9175 


4.9087 


1 


8.802 


6.913 


2.6406 


2.0739 


5.1051 


fJ 


9.492 


7.455 


2.8477 


2.2365 


5.3014 


1 ' 


10.21 


8.018 


3.0625 


24053 


6.4978 


H 


10.95 


8.601 ^ 


3.2852 


2.5802 


5.6941 


} 


11.72 


9.204 


3.5156 


2.7612 


6.8905 


t» 


12.61 


9.828 


3.7539 


2.9483 


.6.0868 



•:^^ 



SQUARE AND ROUND BARS. 

(continued.) 



'Thickness 


Weight of 


Weight of 


Area of 


Area of 


CircumferenM 


3r Di&meter 


QBar 


O B" 


QBar 


O Bar 


of O B*' 


in Inches. 


One Foot long. 


One Foot long. 


in sq. inches. 


in Bq. inches. 


In inches. 


2 


13.33 


10.47 


4.0000 


3.1416 


6.2832 


ih 


14.18 


11.14 


4.2539 


3.3410 


6.4795 


i 


15.05 


11.82 


4.5156 


3.6466 


6.675& 


I 


15.05 


12.63 


4.7852 


3.7583 


6.8722 


i 


16.88 


13.25 


5.0625 


3.9761 


7.0686 


h 


17.83 


14.00 


6.3477 


4.2000 


7.2649 


A 


18.80 


14.77 


5.6406 


4.4301 


7.4613 


;.9.80 


16.55 


6.9414 


4.6664 


7.6576 

- 


\ 


20.83 


16.36 


6.2500 


4.9087 


7.8540 


A 


21.89 


17.19 


6.5664 


6.1572 


8.0503 


¥ 


22.97 


18.04 


6.8906 


5.4119 


8.2467 


ft 


24.08 


18.91 


7.2227 


6.6727 


8.4430 


i 


25.21 


19.80 


7.5625 


5.9396 


8.63d4 


ft 


26.37 


20.71 


7.9102 


6.2126 


8.8357 


Y 


27.55 


21.64 


8.2656 


6.4918 


9.0321 


H 


28.76 


22.59 


8.6289 


6.7771 


9.2284 


3^ 


30.00 


23.56 


9.0000 


7.0686 


9.4248 


t 


81.26 


24.5$ 


9.3789 


7.3662 


9.6211 


32.55 


25.67 


9.7656 


7.6699 


9.8178 


A 


33.87 


26.60 


10.160 


7.9798 


10.014. 


A 


35.21 


27,65 


10.663 


8.2958 


10.21O 


36.58 


28.73 


10.973 


8.6179 


10.407 


A 


37.97 


29.82 


11.391 


8.9462 


10.603 


39.39 


30.94 


11-816 


9,2806 


10.799 


i 


40.83 


32.07 


12.250 


9.6211 


10.996 


A 


42.30 


33.23 


12.691 


9.9678 


11.192 


¥ 


43.80 


34.40 


13.141 


10.321 


11.388 


ft 


45.33 


35.60 


13.598 


10.680 


11.686 


} 


46.88 


36-82 


14.063 


11.045 


11.781 


if 


48.45 


38.05 


14.635 


11.416 


11.977 


^ 


I 50.05 


39.31 


15.016 


11.793 


12.174 


t* 


I. 51.68 


40.59 


15.604 


12.177 


12.370 



S9^ 

SQUARE AND ROUND BARS. 

(continued.) 



Thickness 
ir Diameter 
"In Inches. 


Weight of 
One Foot long. 


Weight of 
One i-'oot long. 

41.89 
43.21 
44.55 
45.91 


Area of 

QBar 

in sq. inches. 


Area of 
^ Bar 
in sq. inches. 


Circnrnferenc- 
of Bar 
in inches. 


4 

t 

T"5 


53.33 
65.01 
66.72 
68.45 


16.000 
16.504 
17.016 
17.535 


;2.566 
12.962 
13.364 
13.772 


12.566 

12.763 

12.959 

• 13.155 


A 
A 


60.21 
61.99 
63.80 

65.64 


47.29 
48.69 
60.11 
51.55 


18.063 
18.598 
19.141 
19.691 


14.186 
14.607 
15.033 
15.466 


13.352 
13.548 
13.744 
13.941 


\ 

A 


67.60 
09.39 
71.30 
73.24 


53.01 
64.50 
56.00 

57.52 


20.250 
20.816 
21.391 
21.973 


15.904 
16.349 
16.800 
17.257 


14.137 
14.334 
14.53a 
14.726 

14.923 
15.119 
15.315 
15.512 


t 


75.21 
77.20 
79.22 
81.26 


59.07 
60.63 
62.22 
63.82 


22.563 
23.160 
23.766 
24.379 


17.721 
18.190 
18.665 
19.147 


5 

t 


83.33 
85.43 
87.55 
89.70 


65.45 
67.10 
68.76 
70.45 


25.000 
25.629 
26.266 
26.910 


19.635 
20.129 
20.629 
21.135 


15708 
15.904 
16.101 
16.297 


1 


91.88 
94.08 
96.30 
88.55 


72.16 
73.89 
75.64 
77.4C> 


27.563 
28.223 
28.891 
29.566 


21.648 
22.166 
22.691 
23.221 


16.493 
16.690 
16.886 
17.082 


A 
A 


100.8 
103.1 
105.5 
107.8 


79.19" 
81.00 
82.83 
84.69 


30.250 
30.941 
31,641 
32.348 


23.758 
24.301 
24.850 
25.406 


17.279 
17.475 
17.671 
17.868 


1 


110.2 
112.6 
115.1 
117.5 


86.66 
88.45 
90.36 
92.29 


33.063 
33.785 
34.516 
35.254* 


25.967 
26.535 
27.10G 
27.688 


18.064 

.a8.261 

^i8.457 

18.653 



SQUARE AND ROUND BARS., 

(continued) 





"Wpigbl of 


Weight of 


Area of 


Area of 


Circumfereuw 


» Diameter 


D"" 


O B" 


□ B.r 


O Bar 


of O Bar. 


in Inches. 


One Foot long 


One fool long. 


m sq. inches. 


in sq. inchus, 

28.274 


in inches; 


6 


120.0 


94.25 


36.000 


18.850 


t 


122-5 


96.22 


36.754 


28.866 


19.046 


126.1 


98.22 


37.516 


' 29.465 


19.242 


127.6 


100.2 


38.285 


30.069 


19.439' 




130.2 


102.3 


39.063 


30.680 


19.635 


132.8 


104.3 


39.848 


31.296 


19831 


135.5 


106.4 


40.641 


31.919 


20.028 


A 


138.1 


108.5 


41.441 


32.548 


20.224 


[^ 


140.8 


110.6 


42.250 


33 183 


20.420 


'9 


143.6 


112.7 


43.066 


33.824 


20.617 


1 


146.3 


114.9 


43.891 


34.472 


20.813 


U 


149.1 


117.1 


44.723 


35.125 


21.O09 


1 


151.9 


119.3 


45.563 


35785 


21.2J06 


li 


154.7 


121.5 


46.410 


36.450 


21.402 


1 


157.6 


123.7 


47.266 


37.122 


21.598 


A 


160.4 


126.0 


48.129 


37.800 


21.79^ 


V 


163.3 


128.3 


49.000 


38.485 


21,991 


' t's 


166.3 


130.6 


49.879 


39.175 


22.187 


J 


169.2 


132.9 


50.706 


39.871 


B2.384 


A^ 


172.2 


135.2 


51.660 


40.574 


22.580 


'J 


175.2 


137.^ 


:&2.563 


41.282 


22.777 


f5 


178.2 


140.0 


53.473 


41.997 


22.973 


'? 


181.3 


142.4 


54.391 


42.718 


23.169 


X 


184.4 


144.8 


55.316 


43.445 


23.360 


} 


187.5 


147.3 


56.250 


44.179 


23.562 


iV 


190.6 


149.7 


57.191 


44.918 


23.758 


i 


193.8 


152.2 


58.141 


45.664 


2^955 


ii- 


197.0 


154.7 


59.098 


46.415 


24.151 
24.347 


'f 


200.2 


157.2 


60.063 


47.173 


ft 


203.5 


159.8 


61.035 


47.937 


?4.544 


i 


206.7 


162.4 


62.016 


48.707 


L4.740 


H ■ 


210.0 


164.9 


63.004 


49.483 


24.930 



594 

SQUARE AND ROUND BARS. 

(continued.) 




irca of 

□ Bar 

Id sq. inchos. 



64.000 
65.004 
66.016 
67.035 

68.063 
69.098 
70.141 
71.191 

72.250 
73.316 
74.391 
75.473 

76.663 
77.660 
78.766 
79.879 

81.000 
82.129 
83.266 
84;410 

85.563 
86723 
87^91 
69.066 

90.250 

91.441 

< 92.641 

93.848 

96.063 
96.285 
97.516 
98.754 



Area of 

O Bar 

in sq. inches. 



50.265 
51.054 
51,849 
52.649 

53.456 
54.269 
55.088 
65.914 

66.745 
67.583 
58.426 
69.276 

60.132 
60.994 
61.862 
62.737 

63.617 
64.504 
65.397 
66.296 

67.201 
68.112 
69.029 
69.953 

70.882 
71.818 
72.760 
73.708 

74.662 
75.622 
76.589 
77.561 



Circumfercnct 

of O B^ 

in inches. 



30.631 
30.827 
31.023 
31.22a 



195 



SQUARE AND ROUND BARS. 

(CONUINUED.) 



TJiickness 
XDiameter 
ts^shea. 


> 
Weight of 
□ Bar 

One Foot long. 


Weight of 

O Bar 

One Foot long. 


Area of 

□ Bar 
in sq. inches. 


Area of 
O Bar 

in sq. inches. 


10 


333.3 

.^37.5 
341.7 
346.0 


261.8 
265.1 
268.4 
271.7 


100.00 
101.25 
102.52 
103.79 


78.540 
79.525 
80.516 
81.513 


1 


350.2 
354.5 
358.8 
863.1 


276.1 

>78.4 
2181.8 
286.2 


105.06 
106.35 
107.64 
108.94 


82.516 
83.525 
84.641 
86.562 


i 

t 


367.5 
371.9 
376.3 
380.7 


288.6 
292.1 
295.6 
299.0 


' \ 10.25 
Si::l.57 
112.89 
114.22 


86.590 
87.624 
88.664 
89.710 


t 


385.2 
389.7 
394.2 
398.8 


302.5 
306.1 
309.6 
313.2 


115.66 
116.91 
118.27 
119.63 


90.763 

92.886 
93.966 


11 

t 


403.3 
407.9 
412.6 
417.2 


316.8 
320.4 
324.0 
327.7 


121.00 
122.38 
123.77 
126.16 


95.033 
96.116 
97,205 
98.301 


} 


421.9 
426.6 
431.3 
436.1 


331.3 
335.0 
338.7 
342.5 


126.56 
127.97 
129.39 
130.82 


99.402 
100.51 
M)1.62 
102.74 


i 


440.8 
445.6 
450.6 
455.3 


346.2 
350.0 
353.8 
357.6 


132.25 

133.69 

, 135.14 

136.60 


103.87 
105.00 
106.14 
107.28 


1 


460.2 
465.1 
470.1 
476.0 


361.4 
365.3' 
369.2 
373.1 


138.06 
139.54 
141.02 
142.60 


108.43 
109.59 
110.75 
111.92 



Girdunferenoi 
of O Bar 

in inches. 



31.416 
31.612 
31.809 
32.005 

32.201 
32.398 
32.694 
32.790 

32.987 
33.183 
33.379 
33.576 

33.772 
33.968 
34.165 
34.361 

f 

' 84.658 
34.754 
34.950 
35.147 

35.343 
35.539 
36.736 
36.932 

36.128 
36.325 
36.521 
36.717 

36.914 
37.110 
37.306 
37,603 



X96 

Weight of Sheets of \A^rought Iron, Steel Cofm 
per and Brass. (From Haswell.) 

WeigMper Square Foot. Thickness by Birmingham Gauge, 



.G«ige. 


Thickness 
in inches. 


Iron. 


Steel. 
18.46 


Copper. 


Brass. 


0000 


.454 


18.22 


20.57 


19.43 


iOOO 


.425 


17.05 


17.28 


19.25 


18.19 


^00 


.38 


15.25 


15.45 


17.21 


16.20 





.34 


11 64 


a3.82 


15.40 


14.55 


1 


.3 


12.04 


12.20 


13.59 


12.84 


2 


.284 


11.40 


11.55 


12.87 


12.10 


3 


.259 


10.39 


10.53 


11.73 


11.09 


4 


.238 


9.55 


9.68 


10.78 


10.19 


6 


.22 


8.83 


8.95 


9.97 


9.42 


6 


.203 


8.15 


8.25 


9.20 


8.09 


7 


.18 


7.22 


7.32 


8.15 


7.70 


8 


.105 


6.62 


6.71 


7.47 


7.00 


9 


.148 


5.94 


6.02 


6.70 


6.33 


10 


.134 


5.38 


5.45 


6.07 


5.74 


11 


.12 


4.82 


4.88 


5.44 


5.14 


12 


.109 


4.37 


4.43 


4.94 


4.07 


13 


.095 


3.81 


3.86 


4.30 


4.07 


14 


.083 


3.33 


3.37 


3.76 


3.55 


16 


.072 


2.89 


2.93 


3.26 


3.08 


10 


.065 


2.61 


2.64 


2.94 


2.78 


17 


.058 


2.33 


2.36 


2.63 


2.48 


(18 


.049 


1.97 


1.99 


2.22 


2.10 


19 


.042 


1.69 


1.71 


1.90 


1.80 


'20 


.035 


1.40 


1.42 


1.59 


1.50 


•21 


.032 


1.28 


1.30 


145 


1.37 


/22 


.028 


1.12 


1.14 


1.27 


1.20 


23 


.025 


1.00 


1.02 


1.13 


1.07 


24 


.022 


.883 


.895 


1.00 


.942 


25 


.02 


.803 


.813 


.906 


.850 


'26 


.018 


.722 


.732 


.815 


.770 


27 


.016 


.642 


.651 


.725 


.685 


.28 


.014 


.562 


.569 


.634 


.599 


I29 


.013 


.522 


.529 


.589 


.550 


30 


.012 


.482 


.488 


.544 


.514 


31 


.01 


.401 


.407 


.453 


.428 


;32 


.009 


.361 


.366 


.408 


.385 


33 


.008 


.321 


.325 


.362 


.342 


34 


.007 


.281 


.285 


.317 


.300 


, 35 


.005 


.201 


.203 


.227 


.214 


Spfdfic G 
,Weight C 


ravity, 
ubic Foot, 


7.704 


7.806 


8.698 


8.218 


481.25 


487.75 


543.6 


513.0 V 


»( 


" Inch, 


.2787 


.2823 


'^149 


.2979 



ii9/ 



^A/'eight of Sheets of Wrought Iron, Steel, Cop* 

per and Brass. From Haswell. 

Weight per Square Foot. Thickness by American (Brown 8z 
Sharpe's) Gauge. 



No. of 

Gauge. 


Thickness 
in inches. 


Iron. 


Steel. 


Copper. 


Brass. 


0000 


.46 


18.46 


18.70 


20.84 


19.69 


000 


.4096 


16.44 


16.66 


18.56 


17.53 


00 


.3648 


14.64 


14.83 


16.53 


15.61 





.3249 


13.04 


13.21 


14,72 


13,90 


1 


.2893 


11.61 


11.76 


13.11 


12.38 


2 


.2576 


10.34 


10.48 


11.67 


11.03 


3 


.2294 


9.21 


9.^3 


10.39 


9.82 


4 


.2043 


8.20 


8.31 


9.26 


8.74 


5 


.1819 


7.30 


7.40 


8.24 


7.79 


6 


.1620 


6.50 


6.59 


7.34 


6.93 


7 


.1443 


5.79 


5.87 


6.54 


6.18 


8 


.1285 


5.16 


6.22 


6.82 


5.50 


9 


.1144 


4.59 


4.65 


5.18 


4.90 


10 


,1019 


4.09 


4.14 


4.62 


4.36 


11 


.0907 


3.64 


3.69 


4.11 


3.88 


12 


.0808 


3.24 


3.29 


3.66 


3.46 


13 


.0720 


2.89 


2.93 


3.26 


3.08 


14 


< .0641 


2.57 


2.61 


2.90 


2.74 


15 


.0571 


2.29 


2.32 


2.59 


2.44 


16 


.0508 


2.04 


2.07 


2.30 


2.18 


17 


.0453 


1.82 


1.84 


2.05 


1.94 


18 


.0403 


1.62 


1.64 


1.83 


1.73 


19 


.0359 


1.44 


1.46 


1.63 


1.54 


20 


.0320 


1.28 


1.30 


1.45 


1.37 


21 


.0285 


1.14 


1.16 


1.29 


1.22 


22 


.0253 


1.02 


1.03 


1.15 


1.08 


23 


.0226 


.906 


.918 


1.02 


.966 


24 


.0201 


.807 


.817 


.911 


.860 


25 


.0179 


.718 


.728 


.811 


.766 


26 


.0159 


.640 


.648 


.722 


.682 


27 


.0142 


.570 


.577 


.643 


.608 


28 


.0126 


.507 


.514 


.573 


.541 


29 


.0113 


.452 


.458 


.510 


.482 


30 


.0100 


.402 


.408 


.454 


.429 


31 


.0089 


.358 


.363 


.404 


.382 


32 


.0080 


.319 


.323 


.360 


.340 


33 


.0071 


.284 


.288 


.321 


.3031 


34 


.0063 


.253 


.256 


.286 


.270 


35 


.0056 


.225 


.223 


.254 


. .240; 



19^ 

WEIGHTS OF FLAT ROLLED IRON PER 

LINEAL FOOT. 

For Thicknesses from 1-16 in. to 2 in., and 

Width from i in. to 12^ in. 

Iron weighing 480 lbs. per cubic foot. 



Thickness 
in Inches. 


1'' 


IK" 


IK'' 

.313 


IH" 


2" 


2H'' 


2K" 


2^" 


12'^ 


^ 


.208 


.260 


.365 


.417 


.409 


.521 


.573 


2.50 


i 


.417 


.521 


.625 


.729 


.833 


.938 


1.C4 


1.15 


5.C0 


A 


.625 


.781 


.938 


1.09 


1.25 


1.41 


1.56 


1.72 


7.50 


i 


.833 


1.04 


1.25 


1.46 


1.67 


1.88 


2.08' 


2.29 


19.00 


A 


1.04 


1.30 


1.58 


1.82 


2.08 


2.34 


2.G0 


2.8G 


12.50 


f 


1.25 


1.56 


1.88 


2.19 


2.50 


2.81 


8.13 


3.44 


15.C0 


1.46 


1.82 


2.19 


2.55 


2.92 


3.28 


8.C5 


4.01 


17.50 


V 


1.67 


2.08 


2.50 


2.92 


3.33 


3.75 


4.17 


4.58 


20,00 


j's 


1.88 


2.34 


2.81 


3.28 


8.75 


4.22 


4.C9 


5.10 


22.50 


i 


2.08 


2.G0 


3.13 


3.G5 


4.17 


4.C9 


5.21 


5.73 


25.C0 


H 


2.29 


2.86 


3.44 


4.01 


4.58 


5.16 


5.73 


6.0O 


27.50 




2.50 


3.13 


3.75 


4.38 


5.00 


5.63 


6.25 


6.88 


30.C0 


U 


2.71 


3 39 


4.06 


4.74 


5.42 


6.09 


6.77 


7.45 


82. 50 


i 


2.92 


3.G5 


4.38 


5.10 


5.83 


6.56 


7.29 


8.02 


35.C0 


H 


3.13 


3.91 


4.69 


5.47 


6.25 


7.03 


7.81 


8.59 


87.50 


t 

i 


3.33 


4.17 


5.00 


5.83 


6.67 


7.50 


8.33 


9.17 


40.00 


lA 


3.54 


4.43 


5.31 


6.20 


7.08 


7.97 


8.85 


9.74 


42.50 


li 


3.75 


4.69 


5.63 


6.56 


7.50 


8.44 


9.38 


10.31 


45.C0 


>t^ 


3.96 


4.95 


5.94 


6.93 


7.92 


8.91 


9.90 


10.89 


47.50 


)^i 


4.17 


5.21 


6.25 


7.29 


8.33 


9.38 


10.42 


11.46 


50.00 


Wz 


4.37 


5.47 


6.56 


7.66 


8.75 


9.84 


10.94 


12.03 


52.50 


If 


4.58 


5.73 


6.88 


8.02 


9.17 


10.31 


11.46 


12.60 


55.00 


ti^ 


4.79 


5.99 


7.19 


8.39 


9.58 


10.78 


1198 


13.18 


57.50 


u 


5.00 


6.25 


7.50 


8.75 


10.00 


11.25 


12.50 


13.75 


60.00 


1t\ 


5.21 


6.51 


7.81 


911 


10.42 


11.72 


13 02 


14.32 


62.50 


If 


5.42 


6.77 


8.13 


9.48 


10.83 


12.19 


13.54 


14.90 


65.00 


Ml 


5.63 


7.03 


8.44 


9.84 


11.25 


12.66 


14.06 


15.47 


67.50 


U 


5.83 


7.29 


8.75 


10.21 


11.67 


13.13 


14.58 


16.04 


70.00 


m 


6.04 


7.55 


9.06 


10.57 


12.08 


13.59 


15.10 


16.61 


72.50 


u 


6.25 


7.81 


9.38 


10.94 


12.50 


14.06 


15.63 


17.19 


75.00 


HI 


6.46 


8.07 


9.69 


11. -30 


12.92 


14.53 


16.15 


1776 


77.50 


2 


6.67 


8.33 


10.00 


11.67 


13.33 


15.00 


16.67 


18.33 


80.00 



3199 



WEIGHT OF FLAT ROLLED IRON PER 
LINEAL FOOT. 



(continued.) 



3" 


SH" 


729 


.625 


.677 


1.25 


1.35 


146 


1.88 


2.03 


2.19 


2.50 


2.71 


2.92 


3 13 


3 39. 


3.65 


375 


4 06 


4U 


4.38- 


474 


5.10 


5.00 


5.42 


5.83 


5.63 


6.09 


6.56 


6.25 


6.77 


7.29 


6.88 


7.45 


8.02 


7.50 


8.13 


8.75 


8.13 


8.80 


9 48 


8.75 


9,48 


10.21 


9.38 


10.16 


10.94 


10.00 


10.83 


11.67 


10.63 


1151 


12.40 


11.25 


12.19 


13.13 


11.88 


12.86 


13.85 


12.50 


13.54 


14.58 


13.13 


14.22 


15.31 


13.75 


14 90 


16.04 


14.38 


15.57 


16.77 


15.00 


16.25 


17.50 


15.63 


16.93 


18.23 


16.25 


17.60 


18.95 


16.88 


18.28 


19.69 


17.50 


18.96 


20.42 


18.13 


19.C4 


21.15 


18.75 


20.31 


21.88 


19.38 . 


20.99 


22.60 


20.00 


21.67 


23.33 



SK" 


..^ 


4^" 


4,4" 


4K" 


12" 


.781 
1.56 
2 34 
3.13 


.833 
167 

2 50 

3 33 


.885 
1.77 
2.66 
3.54 


.938 
1.88 
2.81 
3.75 


,990 
1.98 
2.97 
396 


2.50 

5.00 

7.50 

10.00 


3.91 
4 69 
5.47 
6.25 


4 17 

5 00 
6.83 
6.67 


4.43 
5.31 
6.20 
7.08 


4.69 
5 63 
6.56 
7.50 


4.95 
5.94 
6.93 
7.92 


12.50 
15.00 
17.50 
20.00 


7.03 
7.81 
8.59 
9.38 


750 

8.33 

9.17 

10.00 


7 97 

8.85 

9.74 

10.63 


8 44 

9 38 
10.31 
11.25 


8.91 

9.90 

10.89 

11.88 


22.50 
25.00 
27.50 
30.00 


10.16 
10.94 
11.72 
12.50 


10.83 
11.67 
12.50 
13.33 


11.51 
12.40 
13.28 
14.17 


12.19 
13.13 
14.06 
15.00 


12.86 
13.85 
14.84 
15-83 


S2.5O 
35.00 
37.50 
40.00 


13.28 
14.06 
14.84 
15.63 


14.1-7- 
ISLOO 
15.83 
16.C7 


L5,05 
15.94 
1&82 
17.71 


15.94 
10.88 
17.81 
18.75 


16.82 
17.81 
18.80 
19.79 


42.50" 
45.00 
47.50 
50.00 


16.41 
17.19 
17.97 
18.75 


17.50 
18.33 
19.17 
20.00 


18.59 
19.48 
20.36 
21.25 


19.C9 
20.63 
21.56 
22.50 


20.78 
21.77 
22.76 
23.75 


52.b0 
55.00 
57.50 
60.00 


19.53 
20.31 
21.09 
21.88 


20.83 
21.67 
22.50 
23.33 


22.14 
23.C2 
23.91 
24.79 


23.44 
24.38 
25.31 
26.25 


24.74 
25.73 
26.72 
27.71 


02.50 
05.00 
C7.60 
70.00 


22.66 
23.44 
24.22 
25.00 


24.17 
25.00 
25.83 
26.67 


25.68 
26.56 
27.45 
28.33 


27.19 
28.13 
29.06 
30.00 


28.70 
29.C0 
30.G8 
31.G7 


72.00 
75.00 
77.5a 
CO.OO 



VA«] 



WEIGHTS OF FLAT ROLLED IRON PEB 

LINEAL FOOT. 

(continued.) 



Thickness 
k Inches. 


5" 


5^" 


SK" 


5K" 
1.20 


1.25 


6M" 

1.30 


1.35 


1.41 


12" 


tV 


1.04 


1.09 


1.15 


2.50 


i 


2.08 


2.19 


2.29 


2.40 


2.50 


2.60 


2.71 


2.81 


5.00 


A 


3.13 


3.28 


3.44 


3.59 


3.75 


3.91 


4.06 


4.22 


7.50 


i 


4.17 


4.38 


4.58 


4.79 


5.00 


6.21 


6.42 


5.63 


10.00 


-^z 


5.21 


5.47 


573 


5 99 


6.25 


6.51 


6.77 


7.03 


12.50 


1 


6.25 


6.56 


6.88 


7.19 


7.50 


7.81 


8.13 


8.44 


15.00 


A 


7.29 


7.66 


8.02 


8.39 


8.75 


9.11 


9.48 


9.84 


17.50 


? 


8.33 


8.75 


9.17 


9.58 


10.00 


10.42 


10.83 


11.25 


20.00 


t\ 


9.38 


9.84 


10.31 


10 78 


11.25 


11.72 


12.19 


12.66 


22.50 


f 


10.42 


10.94 


11.46 


1198 


12.50 


13.02 


13.54 


14.06 


25.00 


H 


11.46 


12.03 


12.60 


13.18 


13.75 


14.32 


14.90 


15.47 


27.50 


f 


12.50 


13.13 


13.75 


14.38 


15.00 


15.63 


16.25 


16.88 


30.00 


if 


13.54 


14.22 


14 90 


15.57 


16.25 


16.93 


17.60 


18.28 


32.50 


i 


14.58 


15,31 


16.04 


16.77 


17.50 


18.23 


18.96 


19.69 


35.00 


H 


15.63 


16.41 


17.19 


17.97 


18.75 


19.53 


20.31 


21.09 


37.50 


1 


16.67 


17.50 


1833 


19.17 


20.00 


20.83 


21.67 


22.50 


40.00 


W-. 


17.71 


18.59 


19.48 


20.36 


21.25 


22.14 


23.02 


23.91 


42.50 


li 


18.75 


19.69 


20.63 21.56 


22.50 


23.44 


24.88 


25.31 


45.00 


^A 


19.79 


20.78 


2177 


22.76 


23.75 


24.74 


25.73 


26.72 


47.5C 


ii 


20.83 


21.88 


22.92 


23.96 


25.00 


26.04 


27.08 


28.13 


50.00 


1^ 


21.88 


22.97 


24.06 


25.16 


26.25 


27.34 


28.44 


29.53 


52.50 


H 


22.92 


24.06 


25.21 


26.35 


27.50 


28.65 


29.79 


30.94 


55.00 


lA 


23.96 


25.16 


26.35 


27.55 


28.75 


29.95 


81.15 


32.34 


57.50 


li 


25.00 


26.25 


27.50 


28.75 


30.00 


31.25 


32.50 


33.75 


60.00 


1t\ 


26.04 


27.34 


28.65 


29.95 


31.25 


32.55 


33.85 


35.16 


62.50 


H 


27.08 


28.44 


29.79 


31.15 


32.50 


33.85 


35.21 


36.56 


65.00 


M-i 


28.13 


29.53 


30.94 


32.34 


83.75 


35.16 


36.56 


37.97 


67.50 


H 


29.17 


30.63 


32.08 


83.54 


35.00 


36.46 


37.92 


39.38 


70.00 


HI 


30.21 


31.72 


33.23 


34.74 


36.25 


37 76 


39.27 


40.78 


72.50 


^^ » 


31.26 


32.81 


34.38 


35.94 


37.50 


39.06 


40.63 


42.19 


76.00 


HI * 


32.29 


33.91 


35.52 


37.14 


38 75 


40.36 


41.98 


43.59 


77^0 


e 


33.33 


35.00 


36.67 


38.33 


40.00 


41.67 


43.33 


45.00 


20.00 



SOI 



WEIGHTS OF FLAT ROLLED IRON PER 
LINEAL FOOT. 



(continued.) 



Thiebiesa 
in laehaa. 


7" 


7K" 
1.51 


7^" 
1.56 


7H" 
1.61 


8" 

167 


8K" 
1.72 


fe>^'' 


8H" 


12" 


A 


1.46 


1.77 


1.82 


2 50 


i 


2.92 


3.02 


3 13 


3.23 


3.33 


3.44 


3.54 


365 


50C 


A 


4.38 


4.53 


4.69 


4.84 


5.00 


516 


5 31 


5.47 


7.50 


4 


6.83 


6.04 


6.25 


6.46 


6.67 


688 


7 08 


7.29 


10.00 


ft 


7.29 


7.55 


7.81 


8.07 


8.33 


8.59 


8.R5 


9.11 


12.50 


i 


8.75 


9.06 


9.38 


9.69 


10 00 


10.81 


10 63 


1094 


15.00 


A 


10.21 


10.57 


10.94 


11.30 


11.67 


12.03 


12.40 


1276 


1750 


i 


1167 


12.08 


12.50 


12.92 


13.33 


13 75 


14.17 


1458 


2000 


ft 


13 13 


13 59 


14.06 


14.53 


15 00 


15 47 


15 94 


16.41 


22 50' 


t 


14.58 


15 10 


15.63 


16.16 


16 67 


17 19 


17 71 


18.23 


25 00 


4 


16.04 


16.61 


17.19 


17 76 


18.38 


18.91 


19 48 


20.05 


27.50 


J 


17.60 


1813 


18,75 


19 38 


20 00 


20.63 


21.25 


2h88 


30.00 


ft 


, 18.96 


19 64 


20 31 


20 99 


2167 


22.84 


23 02 


23.70 


32.50 


i 


20 42 


21 15 


2188 


22.60 


23.33 


24.06 


24.79 


25.52 


35.00 


ft 


2188 


22.66 


23.44 


24.22 


25.00 


25.78 


26.56 


27.34 


37.50 


l'' 


23 33 


24 17 


25.00 


25.83 


26.67 


27.50 


28.33 


2917 


4000 


^I^ 


24 79 


25 68 


26.56 


27.45 


28.33 


29.22 


30:10 


30 99 


42 50 


u 


26.25 


2719 


28.13 


29.06 


30.00 


30.94 


3188 


32.81 


45.00 


^t's 


27.71 


28.70 


29.69 


30.68 


31.67 


32.66 


33.65 


34 64 


47.50 


li 


29.17 


30.21 


31.25 


32.29 


33.38 


34.38 


35 42 


36.40 


50 00 


v« 


30.62 


3172 


32.81 


33.91 


85.00 


36.09 


37 19 '38.28 


52.50 


If 


32.08 


33.23 


34.38 


35.52 


36.67 


37.81 


38.96:4010 


55.00 


III 


33.54 


34.74 


35.94 


37.14 


38.33 


39.53 


40 73 4193 


57.50 


n 


35.00 


36.25 


37.50 


38.75 


40.00 


41.25 


42.50 


43.75 


60.00 


u\ 


36.46 


37 76 


39.06 


40.36 


41.67 


42.97 


44.27 


45.57 


62 50 


lY 


37 92 


39.27 


40.63 


41.98 


43.33 


44.69 


46.04 


47.40 


6,5.00 


»H 


39.38 


40.78 


42.19 


43.59 


45.00 


4641 


47.81 


49.22 


67.50 


ii^ 


•40.g3 


42.29 


43.75 


45.21 


46.67 


48.13 


49.58 


51.04 


70.00 

/ 


HI 


42.29 


43.80 


45.31 


46.82 


48.33 


49.84 


51.35 


52.86 


^2^50 


H 


43.75 


45.31 


46.88 


48.44 


50.00 


51.56 


53.13 


54.69 


75.00 


HI - 


45.21 


46.82 


48.44 


50.05 


51.67 


58.28 


54.90 


56.51 


77.50 


12 


46.67 


48.33 


50.00 


51.67 


53.33 


55.00 


56.67 


58.33 


80.00 



20i 



WEIGHTS OF FLAT ROLLED IRON PER 
LINEAL FOOT. 

(continued.) 



Thickness 
in Incbos. 


9" 


9H^'L 
1.93 


9K" 
1.98 


9K" 
2.03 


2.08 


\0\" 


10^'' 


10|" 

2.24 


12" 


A 


1.88 


2.14 


2.19 


2.50 


A 


3.75 


3.85 


3.96 


4.06 


4.17 


4.27 


4.38 


4.48 


5.00 


5.63 


5.78 


6.94 


6.09 


6.25 


6.41 


6.56 


6.72 


7.50 


i 


7.50 


7.71 


7.92 


8.13 


8.33 


8.54 


8.75 


8.96 


10.00 


,A 


9.38 


9.64 


9.90 


10.16 


10.42 


10.68 


10.94 


11.20 


12.50 


1 


11.26 


11.56 


11.88 


12.19 


12.50 


12.81 


13.13 


13.44 


15.00 


13.13 


13.49 


13.85 


14.22 


14.58 


14.95 


15.31 


15.68^ 


-17.60 


■i 


15.00 


15.42 


15.83 


16.25 


16.67 


17.08 


17.50 


17.92 


20.00 


.A 


16.88 


17.34 


17.81 


18.28 


18.75 


19.22 


19.69 


20.16 


22.50 


.* 


18.75 


19.27 


19.79 


20.31 


20.83 


21.35 


21.88 


22.40 


25.00 


a 


20.63 


21.20 


21.77 


22.34 


22.92 


23.49 


24.06 


24.64 


27.60 


i 


22.50 


23.13 


23.75 


24.38 


25.00 


25.62 


26.25 


26.88 


30.00 


a 


24.38 


25.05 


25.73 


26.41 


27.08 


27.76 


28.44 


29.11 


32.50 


i 


26.25J 


26.98 


27.71 


28.44 


29.17 


29.90 


30.63 


31.35 


35.00 


ii 


28.134 


28.91 


29.69 


30.47 


31.25 


32.03 


32.81 


33.59 


37.50 


r' 


30.00 ; 


80.83 


31.67 


32.50 


33.33 


34.17 


35.00 


35.83 


40.00 


iiA 


31.88 


32.76 


33.65 


34.53 


35.42 


36.30 


37.19 


38.07 


42.50 


i-i 


33.75 


34.69 


35.63 


36.56 


87.50 


88.44 


39.38 


40.31 


45.00 


■lA 


35.63 


36.61 


37.60 


38.59 


89.58 


40.57 


41.56 


42.55 


47.50 


:'r 


37.50 


38.54 


39.68 


40.63 


41.67 


42.71 


43.75 


44.79 


50.00 


ifV 


39.38 


40.47 


41.56 


42.66 


43.75 


44.84 


45.94 


47.03 


52.50 


u 


41.25 


42.40 


43.54 


44.69 


45.83 


46.98 


48.13 


49.27 


65.00 


43.13 


44.32 


45.52 


46.72 


47.92 


49.11 


60.31 


61.51 


67,50 


;' 

4A 


45.00 


46.25 


47.50 


48.75 


60.00 


51.25 


62.60 


63^ 


60.00 


46.88 


48.18 


49.48 


50.78 


62.08 


53.39 


64.69 


65.99 


62.50 


M 


48.75 


50.10 


51.46 


62.81 


64.17 


55.52 


66.88 


68.23 


65.00 


liJ 


50.63 


52.03 


63.44 


64.84 


56.25 


57.66 


69.06 


60.47 


67.60 


if 


52.50 


53.96 


65.42 


56.88 


58.33 


69.79 


61.25 


62.71 


70.00 


^H 


54.38 


55.89 


57.40 


58.91 


60.42 


61.93 


63.44 


64.95 


72.60 


11 


56.25 


57.81 


59.38 


60.94 


62.50 


04.06 


65.63 


07.19 


75.C0 


■m 


58.13 


50.74 


61.35 


62.97 


64.58 


66.20 


67.81 


69.43 


77.50 


2. 


60.00 


61.67 


03.33 


65.00 


66.S7. 


08.33. 


7.0.00, 


71.G7 


80.00 



'^^5 



WEIGHTS OF FLAT ROLLED IRON PER 
LINEAL FOOT. 



(continued.) 



Thickness 
n ! jchcs. 


11" 

2.29 


Hi" 

2.34 


11 r 


11?" 


?: 


2.40 


2.45 


i 


4.58 


4.69 


4.79 


4.90 


T^g 


6.88 


7.03 


7.19 


7.34 


i 


9.17 


,9.38 


9.58 


9.79 


Y> 


11.46 


11.72 


11.98 


12.24 


). 


13.75 


14.03 


14.38 


14.69 


16.04 


16.41 


16.77 


17.14 


h 


18.33 


18.75 


19.17 


19.58 


IZ 


20,63 


21.09 


21.56 


22.03 


t 


22.92 


23.44 


23.96 


24.48 


ii 


25.21 


25.78 


26.35 


26.93 


1 , 


27.50 


28.13 


28.75 


29.38 


M 


2979 


30.47 


31.15 


31.82 


i 


32.08 


32.81 


33.54 


34.27 


H 


34.38 


35.16 


35.94 


36.72 


1 


38.67 


37.50 


38.33 


39.17 


liV 


38.96 


39.84 


40.73 


41.61 


lU 


41.25 


42.19 


43.13 


44.06 


1^ 


43.54 


44.53 


45.52 


46.51 


U 


45.88 


46.88 


47.92 


48.96 


1^ 


48.13 


4952 


50.31 


51.41 


If 


50.42 


61.66 


62.71 


53.85 


Vg 


52.71 


63.91 


55.10 


56.30 


n 


55.00 


56.25 


67.50 


58.75 


ItV 


57.29 


68.59 


69.90 


m.20 


If 


59.58 


60.94 


62.29 


63.65 


m 


61.88 


63.28 


64.69 


66.09 


H 


64.17 


65.63 


67.08 


68.54 


m 


66.46 


67.97 


69.48 


70.99 


\i 


68.75 


70.31 


7188 


73.44 


m 


71.04 


72.65 


74 27 


75.89 


e 


73.33 


75.00 


76.37 


78.33 



12' 




2.50 

5.00 

7.50 

10.00 

12.50 
15.00 
17.50 
20.00 

22.50 
25.00 
27.50 
30.00 

32.50 
35.00 
37.50 
40.00 

42.50 
45.00 
47.50 
50.00 

62.50 
55.00 
67.50 
60.00 

62.60 
65.00 
67.50 
70.00 

72.50 
75.00 
77.50 
80.00 



2.55 

5.10 

7.66 

10.21 

12.76 
15.31 
17.86 
20.42 

22.97 
25.52 
28.07 
30.63 

33.18 
35.73 



40.83 

43.39 
45.94 
48.49 
51.04 

53.59 
56.15 
58.70 
61.25 



66.35 
68.91 
71.46 

74.01 
76.56 
79.11 
81.67 



12i" 


12f" 


2.60 


2.66 


5.21 


5.31 


7.81 


7.97 


10.42 


10.63 


13.02 


13.28 


15.63 


15.94 


18.23 


18.59 


20.83 


21.25 


23.44 


23.91 


26.04 


26.56 


28.65 


29.22 


31.25 


31,88 


33.85 


34.53 


36.46 


37.19 


39.06 


39.84 


4167 


42.50 



44.27 

46.88 
49.48 
62.08 

64.69 
67.29 
69.90 
62.50 

65.10 
67.71 
70.31 
72.92 

75.52 
78.13 
80.73 
83.33 



45.16 
47.81 
50.47 
53.13 

65.78 
68.44 
61.09 
63.75 

66.41 
69.06 
71.72 
74.38 

77.03 
79.6^ 
82.34 
85.00 



3 rt 

o 



■3 » 

■3-0 
^3 



^•3 



|X 



gas 

Sag 



1= 



^.^4 



Weight 



of Rivets, and Round Headed 
Without Nuts, Per loo. 



Bolts 



Length from under head. One cubic foot weighing 480 lbs, 



Length 


■%'' 


J4" 


K" 


^" 


%" 


V 


IK" 


IH'* 


Inches 


Dia. 


Dia. 


Dia. 


Dia. 


Dia. 


Dia. 


Dia. 


Dia. 


IH 


5.4 


12.6. 


21.5 


28.7 


43.1 


65.3 


91.5 


123. 


1^2 


6.2 


13.9 


23.7 


318 


47.3 


70.7 


98.4 


133. 


1% 


6.9 


15.3 


25.8 


34.9 


61.4 


76.2 


105. 


142. 


2 


7.7 


16.6 


27.9 


37.9 


55.6 


81.6 


112. 


150. 


2H 


8.5 


18.0 


30.0 


41.0 


69.8 


87.1 


119. 


159. 


2/2 


9.2 


19.4 


32.2 


44.1 


63.0 


92.5 


126. 


167. 


2^ 


10.0 


20.7 


84.3 


47.1 


68.1 


98.0 


133. 


176. 


3 


10.8 


22.1 


36.4 


50.2 


72.3 


103. 


140.^ 


184 


3M 


11.5 


23.5 


88.6 


53 3 


76 5 


109 


147. 


193. 


3^2 


12.3 


24.8 


40 7 


56 4 


80 7 


114. 


154. 


201. 


s% 


13.1 


26.2 


42.8 


594 


84.8 


120. 


161. 


210. 


4 


13.8 


27.5 


45.0 


62.5 


89 


125. 


167. 


218. 


414 


14.6 


28.9 


47.1 


65.6 


932 


131. 


174 


227. 


4% 


15.4 


30.3 


49.2 


68.6 


97 4 


136. 


181. 


236. 


4M 


16.2 


31.6 


51.4 


717 


102. 


142. 


188. 


244. 


5 


18.9 


33.0 


53.5 


74.8 


106. 


147. 


195. 


253. 


5M 


17.7 


34.4 


556 


77.8 


110. 


153. 


202. 


261. 


5^2 


13.4 


35.7 


57.7 


80.9 


114. 


158. 


209. 


270. 


53^ 


19.2 


371 


69.9 


84.0 


118 


163. 


216. 


278 


6 


20.0 


38.5 


62.0 


87.0 


122. 


169. 


223. 


287: 


614 


21.5 


41.2 


66.3 


93.2 


131. 


180. 


236. 


304.' 


7 


23.0 


43.9 


70.5 


99 3 


139. 


191. 


250 


821. 


7/2 


24.6 


46.6 


74.8 


106. 


147. 


202. 


264. 


888. 


8 


26.1 


49.4 


79.0 


112. 


156. 


213. 


278. 


355. 


81/i 


27.6 


52.1 


83.3 


118. 


164. 


223 


29E 


zr. 


9 


29.2 


54.8 


876 


124. 


173. 


234. 


30i 


m. 


9/2 


80.7 


57.6 


91.8 


130. 


181 


245. 


319. 


406. 


10 


32.2 


60.3 


96.1 


136. 


189. 


256. 


333. 


423. 


10/2 


83.8 


€3.0 


101. 


142. 


198. 


267. 


347. 


440. 


11 


35.3 


65.7 


105. 


148. 


206. 


278. 


361. 


457. 


11^2 


86.3 


68.5 


\m. 


155. 


214. 


289. 


375. 


474. 


12 


38.4 


71.2 


112. 


161. 


223._^ 


300. 


388; 


491. 


Heads, 


1.8 


5.7 


10.9 


13.4 


22.2 


88.0 


57.6 


82;0 



205 

Weight of CAi?r Iron per Lineal Foot, — Example : What is 
\veight of a cast iron plate 2" x 14" x one foot long ? Ans. — The 
thickness multiplied by width equals 28" of sectional area. 

In the sixth column, we find that 87^ lbs. is the weight of a piece 
with a sectional area of 28" and one foot long. 



Area 

laches. 


Lbs. 


Area -r v.. 
Inches. 1 ^^^• 

I 


Area 

Inches 


Lbs. 


{±\ I-b- 


Area 

Inches 


Lbs. 


iV 


.20 


6 


18.75 


21^^ 


67.19 


48 


134.38 


69 


215.63 


Vs 


.39 


G'4 


' 19.53 


22 


68.76 


im 


135.94 


70 


218.76 


tV 


.59 


6V^ 


20.31 


223^ 


70.31 


44 


137.5 


71 


221.88 


% 


.78 


62^f 21.09 


23 


71.88 


441^ 


139.06 


72 


225.0 


A 


.98 


7 


,21.88 
' 22.66 


2sy, 


73.44 


46 


140,63 


73 


228.13 


1 


1.17 


7'4 


24 


75.00 


45>^ 


142.19 


74 


231.25 


1.37 


7)^ 


23.44 


24^ 


76.66 


46 


143.75 


75 


234.38 


V2 


1.56 


75i 


24.22 


26 


78.13 


46^ 


145.31 


76 


237.5 


t\ 


1.76 


8 


25.00 


2by, 


79.69 


47 


146.87 


77 


240.63 


% 


1.95 


s% 


25.78 


26 


81.25 


47^ 


148.44 


78 


243.75 


H 


2.15 


8^ 


26.66 


26)^ 


82.81 


48 


150.00 


79 


249.87 


K 


2.34 


8M 


27.34 


27 


84.38 


48J6 


151.66 


80 


260.00 


H 


2.54 


9 


28.13 


27^ 


85.94 


49 


168.12 


81 


253.12 


,^ 


2.73 


0^ 


28.91 


28 


87.6 


49^ 


164.69 


82 


256.25 


fit 


2.93 


9\i 


29.69 


.28V^ 


89.06 


50 


166.26 


83 


269.88 


1 


3.125 


9?i 


80.47 


29 


90.63 


&oyz 


167.81 


84 


262.6 


11^ 


3.61 


10 


31.25 


29>6 


92.19 


51 


159.38 


85 


266.68 


li^ 


3.91 


myi 


82.03 


30 


93.75 


61K 


160.94 


86 


268.76 


IVb 


4.30 


loy^ 


32.81 


30>^ 


96.31 


52 


162.5 


^7 


271.88 


1}^ 


4.69 


102£ 


33.59 


81 


96.87 


62>6 


164.06 


88 


275.00 


1% 


5.08 


11 


34.38 


81H 


98.44 


53 


166.63 


89 


278,18 


1% 


6.47 


11^ 


85.16 


32 


100.00 


533^ 


167.19 


90- 


281.25 


1% 


5.86 


IVA 


35.94 


823^ 


101.66 


64 


168.76 


91 


284.88 


V 


6.25 


n% 


36.72 


83 


103.12 


5|>^ 


170.31 


92 


287.6 " 


2^H 


6.64 


12 


37.5 


3336 


104.69 


65 


171.88 


98 


290.66 


2'^ 


7.03 


12V^ 


39.06 


34 


106.25 


663^ 


173.44 


' 94 


298.76 


2^/^ 


7.42 


13 


40.68 


34^ 


107.81 


56 


175.00 


95 


296.87 


2^ 


7.81 


13>§' 


42.19 


35 


109.38 


66^ 


176.66 


96 


300.00 


2^ 


8.20 


14 


43.75 


35^ 


110.94 


67 


178.13 


97 


303*18 


2^ 


H.59 


14^,4 


45.31 


36 


112.6 


57}^ 


179.69 


98 


806.26 


2% 


8.98 


15 


46.87 


36>6 


114.06 


58 


181.25 


99 


309.88 


3 


9.38 


l5)/2 


48.44 


87 


115.63 


68J6 


182.81 


100 


812.5 


3^ 


10.16 


16 


50.00 


37)^ 


117.19 


69 


184.38 


101 


315.63 


3H 


10.94 


IC^i^ 


51.56 


38 


118-75 


59}^ 


185.94 


102 
103 
104 
105 
106 


818.75 
322.88 
825.00 
328.13 
331.26 


35i 
4 


11.72 
12 5 


17 

17^2 


63.12 
54.69 


38>^ 
39 


120.31 
121.88 


60 
61 


187.5 
190.63 


4^ 


13.28 


18 


56.25 


39V^ 


123.44 


62 


193.75 


4H 


14.06 


185^ 


67.81 


40 


125.00 


68 


196.87 


107 


384.88 


4^4 


14.84 


19 


69.38 


40J/2 


126.66 


64 


200.00 


108 


337.6 ■ 


6 ® 


lo.63 


19JA 60.94 


41 


128.13 


65 


203.125 


109 


340.68 


&^ 


16.41 


'20 62.5 


4iy. 


129.69 


6« 


206.25 


110 


343.75 


.B^ 


17.19 


'20y, 6 4.06 4 2 1 


131.25 


V 


209.38 


111 


346.87 


b\ 


17.97 


21 1 


65.63] 


42y^| 


182.81 


6b 1 


212.6 


112 


350.0Q 



206 



ILIKEAB EXPANSION OP SUBSTANCES 
BY HEAT. 

To find the increase in the length of a bar of any material due 
to an increase of temperature, multiply the number of degrees 
of increase of temperature by the coefficient for 100 degrees and 
by the length of the bar, and divide by 100. 



Name of Substance. 



Ba)rwood, (in the direction of the 

grain, dry,) ^ 
Brass, (cast,) - 

" (wire,) 
Brick, (fire,) - 

Cement, (Roman,) - . , 

Copper, 

Deal, (in the direction of the grain 
dry,) - 

Glass, (English flint,) - ^ 
" (French white lead,) 

Gold, .... 

Granite, (average,) „ 

Iron, (cast,) - 
*' (soft forged,) ^ 
" (wire,) - 

Lead, - - - 



■":{ 



■'•t 



Marble, (Carrara,) - 

Mercury, 
Platinum, •► 

Sandstone, • 



Silver, - . » 

Slate, (Wales,) ,- • _ . - 
Water, (varies considerably with f 
the temperature,) - - < 



Coefficient for 100 " 
Fahrenheit. 


Coefficiflntfor 180° 

Fahrenheit, or 100 

Centigrade, 


.00020 

TO 

.00031 


.00046 

TO 

00057 


.00104 


.00188 


.00107 


.00193 


.0003 


.0005 


.0008 


.0014 


.0009 


.0017 


.00024 


.00044 


.00045 


.00081 


.00048 


.00087 


.0008 


.0015 


.00047 


.00085 


.0006 


.0011 


.0007 


.0012 


.0008 


.0014 


.0016 


.0029 


.00036 

TO 

.0006 


.00066 

TO 

.0011 


.0033 


.0060 


.0005 


.0009 


.0005 

TO 

.0007 


.0009 

TO 

.0012 


.0011 


.002 


.0006 


.001 


.0086 


.0155 



207 

^A^eight of Bolts per loo, Including Nuts. 



c 









DIAMETER. 


J 












— 

10.60 
11.25 
12. 


■ r'« 


\ 

22.50 
23.82 
25.15 


i 


1 


i 


» 


H 
If 

*2 


4. 

4.35 

4.75 


7. 
7.60 

8. 


16 20 
16.30 
17.40 


39.50 
41.62 
43.75 














69. 






2i 


6.15 


8.50 


12.75 


18.60 


26.47 


45.88 


72. 






n 


6.60 


9. 


13.50 


19.60 


27.80 


48.' 


75. 


116.60 


• 


21 


5.75 


9.60 


14.25 


20.70 


29.12 


60.12 


78. 


121.75 


.. 


8 


6.^25 


10. 


15. 


21.80 

24. 1 


30.45 


52.25 


81. 


126. 




84 


•7. 


11. 


16.50 


33.10 


66.60 


87. 


134.25 


. .. 


4 


7.75 


12. 


18. ' 


26.20 


35.76 


60 75 


93.10 


142.50 


207 


4i 


8.50 


13. 


19.60 


28.40 


38.40 


65. 


99.(^ 


161. 


218 


6 


9.25 


14. 


21. 


30.60 


41.05 


69.25 


105 20 


159.65 


229 


6i 


10. 


15. 


22.60 


32.80 


43.70 


73.50 


111.26 


168.- 


240 


6 


K. ;5 


16. 


24. 


35. 


46.36 


77.75 


117.30 


176.60 


251 


6i 






26.50 


37.20 


49. 


82. 


128.36 


185. 


262 


7 






27.'^ 
28.60 
30. 


39.40 
41.60 
43.80 


51.66 
54.30 
69.60 


86.26 
00.60 
94.75 


129.40 

185. 

141.50 


193.66 

202. 

210.70 


27g 


n 

8 


•■ 


' 


284 






295 


9 




' 


■-.., 


46. 


64.90 


103.26 


153.60 


227.75 


317 


10 


# 


' _ 




48.20 
50.40 


70.20 
75.60 


111.75 
1 20.25 


166 70 
177.80 


244.80 
261.85 


330 




* 


;' 




360 


18 




-' 




52.60 


80 80 


128.7 5 


189.90 


278.90 


382 


la 


$ 




.. : . 


' 


8&10 


137 26 


202 


295 95 


404 


14 


t 


1 • - 






91.40 


115.75 


214.10 


su. 


426 


I& 






. ,. . . 





96.70 


154 25 


226.20 


330 05 


448 


IH 






r 




102. 
107.30 


162.75 
171. 


238.30 
250.40 


347.10 
364 15 


470 


n 






' 


f 


492 


■ 8 




■■■:-] 




•" 


112.60 


179.50 


262.60 


381 20 


514 


19 


\ 






...'.... 


117.90 


188. 


274.70 


398.25 


536 


>» 




%..... 1 




■ • I 


123.20 


206 50 


286.80 


415.30 


66^ 



2o8 



TENSILE STRENGTH OF COMMON WOODS. 

Tlie strongest wood which grows within the confines of the 
United States is that known as "nutmeg" hickory, which 
grows in the valley of the lower Arkansas river. The most 
elastic is tamarack. The wood with the least elasticity and 
lowest specific gravity is the Picus aurea. The wood having 
the highest specific gravity is the blue wood of Texas and 
Mexico. 

The heaviest of foreign woods are the pomegranate and 
the lignum vitae; the lightest is cork, which, however, is a 
bark, not solid wood. The tensile strength of the best known 
woods is set forth in the following schedule: 



WOOD. POUNDS, 

Ash 14,000 

Beech 11,500 

Cedar 11.400 

Chestnut 10.500 

Cypress 6.000 

Elm 13.400 

Pir 12.000 

Maple 10.500 

White Oak 11.500 

Pear 9,800 

Pitch Pine 12,000 

Pour hundred and thirteen different species of trees grow 
in the various states and territories, and of tiiis number 16, 
when perfectly seasonable, will sink in water. 



WOOD. POUNDS. 

Larch 9,500 

Poplar 7,000 

Sprace 10,290 

Teak 14,000 

W?^lnut 7,800 

Lance 23,000 

Locust 20,500 

Mahogany 21.000 

Willow 13,000 

Lignum Vitae 11,800 



TEMPERING STEEL PUNCHES. 

Heat your steel to cherry-red, dress out the punch, cut 
off the point the size of a horseshoe nail, then heat to a 
cherry-red, immerse it a half inch perpendicularly in the 
water, then take it out and stand it up perpendicular, clean 
the end with a piece of grinding stone. When you see the 
first blue pass over the point, dip it in the water the same 
depth as before. Clean it again with the stone, and on the 
appearance of the blue again, cool it off. The second blue 
is to make the punch tough. The reason for keeping the 
punch perpendicular is to allow the atmosphere and the 
water to cool all sides equally, and to have it cool straight 
and true. 

HOW TO MAKE TRACING PAPER. 
Take some good thin printing paper, and brush it over on 
one side with a solution consisting of one part, by measure, 
of castor oil in two parts of meth. spirit ; blot off and hang up 
to dry. You can trace by pencil or ink on this. I have tried 
it and done it. 



209 

IN THE SHOP — TURNING A BALL. 

To make a ball as nearly perfect as a billiard ball is made, 

is not a piece of work that often falls to the lot of the 

machinist or pattern-maker ; but occasionally arises the 
necessity for such work. 

In pumping where chips, sawdust, or dust is very liable to 
lodge on the seat under the valve, ball valves are sometimes 
used, because their rolling motion has a tendency to remove 
the obstruction, and let the valve seat fairly again. Some of 
the old-style locomotive pumps had ball valves ; and, in 
tannery work, when small pieces of bark are liable to be ir 
the liquid, ball valves can be used to advantage. 

I have some such valves, four or five inches in diameter, 
for tanner's use. They were of brass, cast hollow, with the 
core holes in the shell plugged. 

I have seen some costly ijiachines which were made for the 
purpose of turning balls ; but I have never seen any better 
work done by them than can be done in a common lathe. 

To make the pattern of a ball, first turn the piece on 
centers, using the calipers to get it approximately near the 
shape, and then cut off the centers. Next make a chuck- 
block of hardwood, A, as shown in the cut, Fig. I. Make 
a cup in the block to receive a small section of the ball, as 
also indicated. A blunt, wood center is sometimes used 
instead of the steel center with a concave piece of copper, as 
represented in cut. Either way will do for making the 
pattern. Put the work in the chuck so as to take the first cut 
around it in the direction of its former centers, or axis. 

Cut lightly, and do not try 
to make a wide space — let it 
be only a narrow ribbon or 
turning — but get it round 
in the direction of present 
evolution ; then change ihe 
chuck so as to make another 
ribbon at right angles to the 
first, the first tool marks 
being the guide for the depth 
of the second cutting. Next 

change the work so as to get 

a ribbon between the other cuts, and continuing this process of 
changing and turning over the whole surface, thus making the 
axis of the pattern of equal length in all directions, and then 
the pattern will be round — it will be a balL At first it might 
seem as if some laying off were needed to get the " ribbons," 




2IO 

as I iiave called them, at right angles to each other, but there 
is no need of that ; by the eye is enough. 

When the machinist comes to finish up the casting, he 
can bolt the chuck-block to his face plate, and use his steel 
center and a concave piece of copper as represented in the 
cut. He will have to use a hand tool, or a scraper, after 
getting under the scale. 

If the ball becomes too small for the cup in the block, it 
is an easy matter to make a new fit by cutting deeper into the 
chuck-block. 

THE ACTION OF SEA-WATER ON CAST-IRON 

PILES. 

I7idia7ta Engineering notes the results of some observa- 
tions made by the chief engineer of the B. B. and C. I. 
Railway on the cast-iron piles forming the piers of the South 
Bassien bridge. The piles were put down in 1862. Two 
were found almost as fresh in appearance as when sunk, and 
showed no corrosions in specimens cut from the metal. The 
deepest corrosion found on any pile was ^\ inch ; and this 
corrosion was the greatest near low-water mark. The pile 
bolts were all in excellent condition. All of these piles have 
been exposed to the action of sea-water for about twenty- 
five years, and the examination was made to set aside^ a current 
suspicion that they were deteriorating under the action of the 
water. 

JAPANESE WATER PIPES. 
The water supply of Tokio, Japan, is by the wooden water 
pipe system, which has been in existence over two hundred 
years, furnishing at present a daily supply of from twenty -five 
to thirty million gallons. There are several types of water 
pipes in use, the principal class being built up with plank, 
square, and secured together by frames surrounding them at 
close intervals. The pipes, less than six inch, consist of bored 
logs, and somewhat larger ones are made by placing a cap on 
the top of a log in which a very large groove has been cut. 
All the connections are made by chamfered joints, and cracks 
are calked with an inner fibrous bark. Square boxes are 
used in various places to regulate the uniformity of the flow 
of the water, which is rather rapid, for the purpose of pre- 
venting aquatic growth. T!*c water is not delivered to the 
houses, but into reservoirs on the sides of the streets, nearly 
11;, 000 in number. 



211 

THE HEATING POWER OF FUEL. 

The heating power of fuel is ascertained by tjie follow dng 
process, which consists in burning one gramme of the co&l or 
fuel in a small platinum crucible, supported on the bow! pf a 
tobacco pipe, and cov'ered by an inverted glass test^ivbe, 
through Avhich is passed a stream of oxygen, while the i/I.ole 
is placed under water in a glass vessel. The oxygen i fed 
into the test tube by a movable copper tube, which ma.^ ^e 
pushed into the test tube so as to come immediately over tW 
crucible. The coals burn away in a few minutes with very 
intense heat, and the hot gases escape through the water, the 
bubbles being broken up by passing through sheets of wire 
gauze which stretch between the test tube and the walls of 
the vessel containing the water in which it is placed. The 
temperature of the water is taken before and after the 
experiment, and, from the figures thus obtained, the heating 
power of the coal is calculated. 

HOW STEEL RULES ARE MADE. 

There are few branches of tne engineering trades that 
require the exactness and precision requisite in the manufact- 
ure of steel rules, standards, and measuring instruments. 

Accuracy and reliability are the two absolute essentials. In 
the general practice the steel blades, after being prepared by 
being ground, glazed, and tempered, are coated by an acid- 
resisting varnish, specially made to suit the requirements of 
the trade, for upon this depends, in a great measure, the 
clearness of the divisions when etched. The varnish being 
dry, the blades are placed upon the table of a pentagraph, 
which might well be termed a copying machine, as its work is 
to transfer to the steel blades, in a diminished size, any markSj 
letters, or figures that may be traced ftom the copy. The 
latter is a plate of thin zinc, or any suitable metal, usually 
four times larger than the rules to be made, the divisions, 
figures, and letters all being made four times larger than they 
are required to be when engraved upon the steel blades; the 
object of this increased size being to diminish any imperfec- 
tion that may exist upon the copy. There is a tracer con- 
nected by a system of steel bands and pulleys to the table so 
constructed as to move in two opposite directions at right 
angles to each other, \bove the table are fixed two rows of 
holders, each having a diamond point; these holders are raised 
and lowered at the will of the operator by a treadle, so that 
both divisions, figures, and letters are traced from the copy 



212 

and transferred in a diminished proportion, to the steel 
blades. The dianwnd points being required only to cut 
through the varnish, the blades are taken from the machine 
and etched, the acid burning away the steel wherever the 
diamond point has been traced. 

A WATER CURTAIN. 

A fire in a large spice mill adjoining the Chicago Public 
Library gave the first opportunity for testing the water cur- 
tain, the apparatus for producing which forms a part of the 
building. Tubes are arranged on the outside of the build- 
ing on the top through which water can be turned, and the 
arrangement proved thoroughly satisfactory. Streams of 
water ponred out of the tubes, covering the walls, and 
owing to the temperature they were coated with ice in a 
few minutes. It looked like a closely woven curtain through 
which the flames and even the heat could not penetrate. 
Not a pane of glass was injured and the paint of the window 
frames did not crack. 

CHEMICAL OR PHYSICAL TESTS FOR STEEL. 

Captain Jones, of the Edgar Thomson Steel Works, 
Pittsburg, was in Edinburgh at the meeting of the Union and 
Steel Institute, and, when invited to speak, said he could not 
let what Mr. Clark had said about the practice of punching 
steel plates in America pass without comment. Punching 
steel plates was a relic of barbarism, and there was an appro- 
priateness about the president's suggestion, to *' punch a man 
who punched a plate." As to the relative cost of punching 
and drilling, he had long since made up his mind about that, 
for many years ago, in constructing a roof, he had drilled all 
the holes and found it cheaper than punching. With regard 
to the use of steel in America, they found boiler-makers, 
bridge-makers and many others using it largely. ^ They had 
started with physical tests, not chemical analysis, but they 
had come to the conclusion that physical tests could be met, 
and yet the metal not be what it should be. The test for 
boil«r plates at the Edgar Thomson Works -was higher than 
that demanded for the boiler plates of the United States 
cruisers, the limit for phosphorus being .035, and manganese, 
.350 per cent. He bad seen steel made in America, where 
the heat had been blown for eight minutes, the manganese 
being put in cold, and he was of opinion that the reaction 
had not taken place up to the time of speaking. With regard 



»«2l 

to steel for bridge construction, he considered that not moif 
than .065 per cent, of phosphorus should be present, and th« 
manganese should be kept low, as that was the great oxidiz- 
ing agent. He would like to see these conditions enforced 
by law. In conclusion he wished to impress on his hearers 
the necessity for judging steel by chemical tests first, and let* 
ting the physical tests be subsidiary to them. 

SUGGESTIONS TO STEEL WORKERS. 

Messrs. Miller, Metcalf & Parkin, of Pittsburgh, have 
issued a pamphlet on this subject. They draw attention to 
the following points : 

Annealing — There is nothing gained by heating a piece 
of steel hotter than a bright cherry -red heat ; on the contrary, 
a higher heat may render the steel harder on cooling than 
would be the case with the heat just mentioned. Besides 
this, the scale formed would be granular, and would spoil the 
tools to be used in working the metal, and the metal itself 
would change its structure, and become brittle. 

Steel should never be left in a hot furnace over night, af^ 
the metal becomes too hot, and is spoilt for after treatment. 

Forge Steel — The difficulty experienced in the forge fire is 
usually due more to uneven heat than to a high temperature. 
If heated too rapidly^ the outside of the bar becomes soft, 
while the inside is still hard, and at too low a temperature for 
treatment. 

In some cases a high heat is more desirable to save heavy 
labor ; but in every case where a fine steel is to be used for 
cutting purposes, it must be borne in mind that every heavy 
forging refines the bars as they slowly cool, and, if the smith 
heats such refined bars until they are soft, he raises the grain, 
makes them coarse, and he cannot get them fine again, unless 
he has a very heavy steam hammer at command, and knows 
how to use it well. 

When the ^steel is hot through, it should be taken from 
the fire immediately, and forged as quickly as possible. 
"Soaking" in the fire causes steel to become "dry" and 
brittle, and does it very great injury. 

Tei7iper — The word " temper," as used by the steelmaker^ 
indicates the amount of carbon in steel ; thus, steel of high 
l<;inper, is steel containing much carbon ; steel of low temper^ 
is steel containing little carbon ; steel of medium temper is 
steel containing carbon between these limits. Between the 
highest and the lowest, there are some twenty divisions, each 
representing a definite Dercentage of carbon. 

The act of tempering steei is the act of giving to a piece 



214 

of steel, after it has been shaped, the hardness necessary for 
the work it has to do. This is done by first hardening the 
piece — generally a good deal harder than is necessary — and 
then toughening it by slow heating and gradual softening until 
it is just right for work. 

A piece of steel, properly tempered, should always be 
finer in grain than the bar from which it is made. If it is 
necessary, in order to make the piece as hard as is required, 
to heat it so hot that after being hardened it will be as coarse 
or coarser in grain than the bar, then the steel itself is of too 
low a temper for the desired purpose. In a case of this kind, 
the steelmaker should at once be notified of the fact, and 
could immediately correct the trouble by furnishing higher 
steel. 

Heating — -There are three distinct stages or times of 
heating : 

First, for forging ; second, for hardening ; third, for 
tempering. 

The first requisite for a good heat for forging is a clean 
fire, and plenty of fuel, so that jets of hot air will not strike 
the corners of the piece ; next, the fire should be regular, and 
give a good uniform heat to the whole part to be forged. It 
should be keen enough to heat the piece as rapidly as possible, 
and allow it to be thoroughly heated through, without being 
so fierce as to overheat the corners. Steel should not bi left 
in fire any longer than is necessary to heat it through ; and, 
on the other hand, it is necessary that it should be hot through 
to prevent surface cracks, which are caused by the reduced 
cohesion of the overheated parts which overlie the colder 
central portion of an irregularly heated piece. 

By observing these precautions, a piece of steel may 
always be heated safely up to even a bright yellow heat when 
there is much forging to be done on it, and at this heat it will 
weld well. The best and most economical of welding fluxes 
is clean, crude borax, which should be first throughly melted, 
and then ground to fine powder. Borax, prepared in this 
wa.y, will not froth on the steel, and one-half of the usual 
quantity will do the work as well as the whole quantity 
un melted. 

After the steel is properly heated, it should be forged to 
shape as quickly as possible ; and, just as the red heat is 
leaving the parts intended for cutting edges, these parts 
should be refined by rapid, light blows, continued until the red 
disappears. 

For the second stage o\ heating, for hardenincr, great 
care should be used, first, to protect the cuttincr ed-jes and 



215 

working parts from heating more rapidly than the body of 
the piece ; next, that the whole part to be hardened be heated 
uniformly through without any part becoming visibly hotter 
than the other. A uniform heat, as low as will give the 
required hardness, is the best for hardening. For every 
variation of heat which is great enough to be seen, there will 
result a variation in grain, which may be seen by breaking 
the piece ; and for every variation in temperature, a crack is 
likely to be produced. Many a costly ^ool is ruined by 
inattention to this point. The effect of too high a heat is to 
open the grain — to make the steel coarse. The effect of an 
irregular heat is to cause irregular grain, irregular strains and 
cracks. 

As soon as the piece is properly heated for hardenmg, it 
should be promptly and thoroughly quenched in plenty of the 
cooling medium — water, brine, or oil, as the case maybe. 
An abundance of the cooling bath, lo do the work quickly 
and uniformly all over, is very necessary to good and satt> 
work ; and to harden a large piece safely, a running stream 
should be used. Much uneven hardening is caused by the use 
of too small baths. 

For the third stage of heating, to temper, the first 
important requisite is again uniformity ; the next is time. 
The more slowly a piece is brought down to its temper, the 
better and safer is the operation. When expensive tools, 
such as taps, rose cutters, etc., are to be made, it is a wise 
precaution, and one easily taken, to try small pieces of the 
steel at different temperatures, so as to find out how low a 
heat will give the necessary hardness. The lowest heat is the 
best for any steel ; the test costs nothing, takes very little 
time, and very often saves considerable loss. 

A NEW BREATHING APPARATUS. 
A new breathing apparatus has been invented by an 
Austrian. It is for use as a rescue apparatus for coal mines 
It consists of an India rubber cloth receptacle made in the 
form of a collar which closely surrounds the wearer's neck> 
serving as a breathing bag, and at the same time to hold a 
store of quickline for absorbing the carbonic acid and water 
vapor. A mask tightly enclosing the face is also employed, 
and oxygen can be breathed from an accompanying con- 
tainer, so that a man wearing these appliances can remain 
in a locality filled with irrespirable gases. It will be pre- 
cious for firemen descending in cellars filled with carbonic 
acid gas, or for well-diggers having to fight sewer gas. 



2l6 

LIQUID HYDROGEN. 

In the spring of 1898, Prof. Dewar, of the British Royal 
Institution, succeeded in liquefying the most volatile of all 
gases, hydrogen. Liquid hydrogen is colorless, transparent, 
and of only one-fourteenth of the density of water. It is 
so cold that it freezes and solidifies air and oxygen instantly. 
In a closed tube brought in contact with it, the air freezes 
into a small lump, leaving the tube a vacuum. 

LARGEST BELT. 

It is said that the largest belt ever made was turned out 
by a Canadian concern. It measures 3,529 feet long and is 
of rubber, its weight being 9 tons. It is made for the grain 
elevator of the Intercolonial Railway at St. Johns, N. B. 

WATCH AND LEARN. 

This is an excellent motto for every young man to adopt, 
and, by a close observance of it, it will prove of great value, 
even after he becomes grown up and starts out in business 
for himself. There is no surer way of gaining knowledge 
than by a careful and understanding watchfulness of others 
in the same line of business as yourself. As an apprentice, 
you cannot expect to know everything, and the best way to 
gain information from others is to show a willingness to 
learn ; then they will take an interest in teaching. But if, 
as is too often the case, a young man, after he has been a few 
months in a place, pretends to know as much, and sometiraes 
more, than those much older and more experienced than him- 
self, he will not get much information from his fellow work- 
men ; neither will he retain their good will for any length of 
time, and may expect to have all manner of practical jokes 
played upon him. As a journeyman, if you are intelligent, 
you will very often have occasion to believe that you do not 
know it all, and, in fact, the longer you live and the more 
you learn, the more you will find that there is to be learned. 
The egotistical and loud man is seldom a perfect man, and is 
generally very far from being as near perfection as he would 
have others think him. The person who, on a first acquaint- 
ance, is anxious to tell you what he knows, and is very free 
in giving advice and information without the asking, generally 
exhausts the supply before very long. He who is willing to 
listen is generally the one whose source of information is 
ilroader and of a more durable, valuable and substantial 
ki>?d An example may prove the idea to be conveyed more 



217 

cleatly. An employer was in want of a good, practical and 
experienced man for a certain class of work. A yotmg 
man applied for the position, who was very certain that he 
" knew all about the machine," and he was engaged. It was 
not long before every man in the shop knew all that he did, 
and one very valuable thing that he did not, and that was 
that he did not know all that he pretended to. His manner 
and braggadacio very soon got most of the men down on 
him. They were not disappointed. The new machine 
arrived, and was set up ready for operation. The young 
man was given a job to be worked off, and began operations 
with that self-conscious air of superiority that is generally 
apparent in characters of this description. One whole day 
he worked at the job, and it was not then in a condition to be 
run. Not only that, but he had shown to the men, who, of 
course, were secretly watching him, that he knew practically 
nothing of the machine. Then he bega-n to lay the blame 
for the trouble upon others, and asked assistance and 
" points " from some of the other workmen. This of course 
he did not get, and finally another man was put on the job, 
and he was discharged amid the taunts and ridicule of the 
others. If the young man had shown good sense when he 
first came into the shop ; not been quite so free to tell all he 
knew, and had shown a willingness to learn, there was not a 
man in the place that would not have gladly assisted him, and 
he might have remained in a good position. It sometimes 
pays to be ignorant, at least a little modesty is a good thing 
to take with you on going to a new place. If you know more 
than you pretend, it will soon be found out, and you will be 
the gainer; but, if you fail to make good your pretensions, not 
only your employer but all your fellow workmen will be 
"down on you," and things will be correspondingly 
unpleasant. 

DEOXIDIZED COPPER. 

The advantages to be obtair«ed by the '"^e of copper as 
nearly chemically pure as possib'% r»re generally admitted, 
whether the metal be used as coppcj; or in the form of brass, 
bronze, or the many other alloys into which it enters. The 
Deoxidized Metal Company, of Bridgeport, Conn., claims 
that the desired result is secured by the process which is used 
in its works. The castings of brass, bronze, etc. , made under 
this process, are most excellent, while the sheet copper and 
brass, and the wire made, when submitted to careful tests, 
show an unusually high degree of strength, copper wire hav- 
ing been tested up to 70,000 lbs. per square inch, tensile 



2l8 

p&rength. The deoxidized metal also possesses the property 
[)f great resistance to acids, so that it can be used for many 
purposes where ordinary metal is soon destroyed by the 
j;hemical action. Journal-bearings made from this metal 
have also been tested with very favorable results, while for 
bells it is claimed that the tone and quality is much superior 
to ordinary brass. 

MAKING JAPANNED LEATHEB. 

Japanned leather, generally called patent leather, was first 
made in America. A smooth, glazed surface is first given to 
calfskin in France. The leather is curried expressly for this 
purpose, and par oicular care is taken to keep as free as pos- 
sible from grease; the skins are then tacked on frames and 
coated with a composition of linseed oil and umber— in the 
proportion of 18 gallons of oil to 5 of umber— boiled until 
nearly solid, and then mixed with spirits of turpentine to its 
proper consistency. Lampblack is also added when the com- 
position is applied, in order to give color and body. From 
three to four coats are necessary to form a substance to re- 
ceive the varnish. They are laid on with a knife or scraper. 
To render the goods soft and pliant each coat must be very 
light and thoroughly dried after each application. 

A. thin coat is afterward applied of the same composition, 
of proper consistency, to be put on with a brush, and with 
sufacient lampblack boiled in it to make a perfect black. 
When thoroughly dry it is cut down with a scraper having 
turned edges. It is then ready to varnish. The principal 
varnish used is made of linseed oil and Russian blue boiled 
to the thickness of printers' ink. It is reduced with spirits 
of turpentine to a suitable consistency to work with a brush 
and then applied m two or three separate coats, which are 
scraped and pumiced until the leather is perfectly filled and 
smooth. 

The finishing coat is put on with special care in a room 
kept closed and with the floor wet to prevent dust. The 
frames are then run into an oven heated to about 175 de- 
gress. In preparing this kind of leather the manufacturer 
must give the skin as high a heat as it can bear, in order to 
dry the composition on the surface as rapidly as possible 
without absorption, and cautiously, so as not to injure the 
fibre of the leather. It is well nigh impossible to guarantee 
the permanency of patent leather, no matter how expensive 
or how careful be the preparation, for it has a sad trick of 
cracking without any justifiable provocation. 



HOW TO LACQUER BRASS. 

It is strange that not one druggist out of ten knows how 

ro compound and put up a first-class lacquer, but depends 

entirely on the manufacturer, who, owing to the general lack 

of knowledge regarding the matter, often imposes upon their 

customers, sending a vastly inferior article. Again, not one 
customer in ten knows how to apply lacquer, and the drug- 
gist is blamed, w^hen the user's ignorance is the cause of 
failure. Let both the dealer and the consumer keep the fol- 
lowing constantly in mind when sellixig or using lacquer : 

Remove the last vestige of oil or grease from the goods 
to be lacquered, and do not touch the work with the fingers. 
A pair of spring tongs or a taper stick in some of the holes 
is the best way of holding. 

Heat the work sufficiently hot to cause the brush to 
smoke when applied, but do not make hot enough to harm 
the lacquer. 

Fasten a small wire across the lacquer cup from side to 
side to scrape the brush on ; the latter should have the ends 
of the hairs trimmed exactly even with a pair of sharp 
scissors. 

Scrape the brush as dry a^ r>cssible on the wire, making a 
flat, smooth point at the same time. 

Use the very tip of the brush to lacquer with, go very 
slow, and carry a steady hand. 

Put on two coats at least. Li order to make a very dura- 
ble coat, blaze off with a spirit lamp or Bunsen burner, taking 
special pains not to burn the lacquer. 

I f the work looks gummy, the lacquer is too thick ; if 
prisaiatic colors show themselves, the lacquer is too thin. In 
the former case, add a little alcohol ; in the latter, place over 
the lamp, and evaporate to the desired consistency. 

If the work is cheap, like lamp-burners, curtain fixtures, 
etc., the goods may be dipped. For this purpose use a bath 
of nitric acid, equal parts, plunge the goods in, hung ou wire, 
for a moment, take out and rinse in cold water thoroughly,^ 
dip inhot water, the hotter the better, removeaud put in alco- 
hol, rinse thoroughly, and dip in lacquer, leaving in but a few 
minutes; shake vigorously to throw off all surplus lacquer, 
and lay in a warm place ; a warm metal plate is the best to 
dry. Do not touch till cool, and the job is done. Lac- 
quered work should not be touched till cold; it spoils the 
polish. 

Sometimes drops will stand on tlie work, leaving a spot. 



220 

These drops are merely little globules of air, and can be 

avoided by shaking when taken out. 

The best lacquer for brass is bleached shellac and alco- 
hol ; simply this, and nothing more. 

In the preparation of goods for lacquering, care should be 
taken to polish gradually, /. ^., carefully graduate the fine- 
ness of materials until the last or finest finish. Then, when 
the final surface is attained, there will be no deep scratches, 
for, of all things to be avoided in fine work, are deep scratches 
beneath a high polish. 

THE REAL INVENTOR OF THE BESSEMER PRO- 

CESS. 

The late William C. Kelly, the world-famed inventor 
of the improved Bessemer process of making steel, was 
years ago, the proprietor of the Suanee Iron Works and 
Union Forge, in Lyon County, Ky. The metal produced at 
these works was taken from the furnace to the forge, where 
it was converted into charcoal blooms. These blooms had a 
great reputation for durability and quality, and were used 
principally for boiler plates and metal. It was while making 
the blooms at this place that Mr. Kelly made his great inven- 
tion of converting iron into Bessemer steel, which Judge 
Kelly of Pennsylvania, at the Masonic Temple Theater last 
fall, termed the greatest invention of the age. The old pro- 
cess of making blooms was very expensive, owing to the 
great amount of charcoal required in its transformation, and 
Mr. Kelly conceived the idea of converting the metal into char- 
coal blooms without the use of fuel, by simply forcing powerful 
blasts of atmosphere up through the molten metal. His idea 
was that the oxygen of the air would unite with the carbon 
in the metal and thus produce combustion, refine the metal, 
and, by eliminating the carbon, wrought-iron or steel would 
be produced. When he announced his theory to his friends 
and to skilled iron workers, they scoffed, and were struck with 
astonishment that a man of Mr. Kelly's learning and practica 
iron-making knowledge would suggest such an idea as boiling 
metal without the use of fuel, and by simply blowing air 
through it. 

His friends thought him demented, and discouraged him 
from wasting his time and money upon any such visionary 
scheme. Mr. Kelly was confident that his idea was a good 
one, and began making experiments, which he kept up with 
varying success for ten years, but the blooms were manufac* 
tuYQd without the aid of fuel. It was generally known as 



221 

" Kelly's air boiling process," and was in daily use convert* 
ing iron into blooms at his forge. Mr. Kelly's customers 
learned finally of the process, and, not understanding it, they 
advised him that they would not buy blooms made by any 
but the old and established method. This was the first diffi- 
culty placed in Mr. Kelly's way, and he was consequently 
compelled to carry on his work secretly, which subjected him 
to many disadvantages. Some English skilled workmen in 
Mr. Kelly's employ were familiar with his non-fuel process, 
and went back to England, taking the secret with them. 
Shortly after their arrival in Liverpool, Kenry Bessemer, an 
English ironmaster, startled the iron world by announcing 
the discovery of the same process as Mr. Kelly's, and applied 
for patents in Great Britain and in the United States. Mr. 
Kelly at once made his application for a patent, and was 
granted one over Bessemer, the decision being that he was the 
first inventor and was entitled to the patent by priority. 

The history of this remarkable invention is a lengthy one, 
and it is generally admitted by persons cognizant of the facts 
in the case that Bessemer' s idea was secured from the English 
ironworkers employed by Mr. Kelly. Certain it is, however, 
that Mr. Kelly's invention and patents have heaped honors 
and w^ealth upon Bessemer, and he has been regarded as 
the greatest inventor of the nineteenth century, and the 
proper credit was always accorded him. Mr. Kelly's process 
was but barely successful until after it was perfected by Rob- 
ert Musshult, a prominent English iron worker. Concern- 
ing the claims of the different persons, a prominent iron and 
steel manufacturer, the late James Park, of Pittsburg, once 
said: " The world will some day learn the truth, and in ages 
to come a wreath of fame will crown William Kelly, the true 
inventor, and that truth will never be effaced by time." 

A NOVEL PLANING MACHINE. 

A iiiachine for planing the curved surfaces of propeller 
blades, so as to render them of uniform thickness and pitch, 
has been invented in England, and is herewith described. 
The principal feature is guiding and controlling the tool to 
travel on the curved surfaces, by a cast-iron former. 

The machine is provided with two tables, which can be 
rotated through a given range by a worm-wheel and worm, 
so that the inclinations of both tables can be simultaneously 
varied, and to an equal degree. One of the tables carries a 
cast-iron copy of the back or front of the blade it is desired 
to produce, while on the other table the actuall propeller is 



222 

secured, one of its blades occupying a similar position on thist 
table ta that of the copy on the other. 

Toin-sure the rigidity of the work, the table on which the 
propelLir is fixed has its iipper surface shaped to correspond 
with thh form of the blade on it, and is finally brought to the 
exact sh'ipe necessary by a coating of Portland cement.- A 
cut ^ ii(i„ deep can be taken without springing the blade. 
The proptiller is also held by being mounted on a duplicate 
of tha propeller shaft, which is secured to the table. The 
cutting io done by a tool of the ordinary type, work being 
commend!?^! at the top of the blade, and a self-acting 
traverse i/ \sed to feed the tool toward the boss. 

The tool-holder is connected by a system of levers with a 
similar holder at the other end of the slide, carrying a 
follower, which moves over the copy, and thus guides the 
cutting tool. As the boss is approached, the inclination of 
the two tables to the horizontal is altered by the worm gear, 
<-o as to limit the necessary vertical motion of the tool. In 
this way all the blades of the propeller may be successfully 
machined, back and front, and will then be of identical form 
and thickness, and set at the same angle to the propeller 
bha't. 

One of the propellers lately turned out by this machine 
^^•as 6 ft. r. diameter, with an increasing pitch, the mean of 
which was / ft. 9 in., the thickness in the center of the blades 
varying from yg in. at the top to i in. at the boss. The 
breadth was 21 in., and the widest part and the cross section 
showed a regular taper from the center line to a knife-edge. 

The importance of accuracy and uniformity in the shape 
of .the blades of propellers for high-speed vessels is now 
generally acknowledged, and the machine we have described 
promises to form a very useful addition to the plant of a 
modern marine engineering establishment. 

HOW TO REMOVE RUST FROM IRON. 

A method of removing rust from iron consists in im- 
mersing the articles in a bath consisting of a nearly saturated 
solution of chloride of tin. The length of time during which 
the objects are allowed to remain in the batk depends on 
the thickness of the coating of rust ; but in ordinary cases 
twelve to twenty-four hours is sufficient. The solution 
ought not to contain a great excess of acid if the iron itself 
is not to be attacked. On taking them from the bath, thf 
articles are rinsed in water and afterward in ammonia. The 
iron, when thus treated, has the appearance of dull silver; 
but a simple polishing will give it its normal appearance. 



HOW TO ANNEAL STEEL. 

Owing to the fact that the operations of rolling or ham* 
mering steel make it very hard, it is frequently necessary 
that the steel should be annealed before it can be conven- 
iently cut into the required shapes for tools. 

Annealing or softening is accomplished by heating steel 
to a red heat, and then cooling it very slowly, to prevent it 
from getting hard again 

The higher the degree of heat the more will steel be 
softened, until the limit of softness is reached, when the steel 
is melted. 

It does not follow that the higher a piece of steel is 
heated the softer it will be when cooled, no matter how 
slowly it may be cooled ; this is proved by the fact that an 
ingot is always harder than a rolled or hammered bar made 
from it. 

Therefore, there is nothing gained by heating a piece of 
steel hotter than a good bright cherry red ; on the contrary, 
a higher heat has several disadvantages : if carried too far, 
it may leave the steel actually harder than a good red heat 
would leave it. If a scale is raised on the steel, this scale 
will be harsh, granular oxide of iron, and will spoil the tools 
used to cut it. It often occurs that steel is scaled inthisway, 
and then, because it does not cut well, it is customary to heat 
it again, and hotter still, to overcome the trouble, while the 
fact is, that the more this operation is repeated, the harder 
the steel will work, because of the hard scale and the harsh 
grain underneath. A high scaling heat, continued for a 
little time, changes the structure of the steel, destroys its 
crystalline property, makes it brittle, liable to crack in hard- 
ening, and impossible to refine. 

Again, it is a common practice to put steel into a hot fur- 
nace at the close of a day's work, and leave it there all night. 
This method always gets the steel too hot, always raises a 
scale on it, and, worse than either, it leaves it soaking in the 
fire too long, and this is more injurious to steel than any other 
operation to ^^hich it can be subjected. 

A good illustration of the destruction of crystalline struc- 
ture by long-continued heating may be had by operating on 
chilled cast-iron. 

If a chill be heated red hot and removed from the fuc as 
soon as it is hot, it will, when cold, retain its |)eculiar crystal- 
line structure; if now it be heated red hot, and left at a 
moderate red for several hours; in short, if it be treated as 
St.eel often is, and be left in a furnace over night, it will be 



found, when cold, to have a perfect amorphous structure, 
every trace of chill crystals will be gone, and the whole piece 
be non-crystalline gray cast-iron. If this is the effect upon 
coarse cast-irons, what better is to be expected from fine cast- 
steel ? 

A piece of fine tap steel, after having been in a furnace 
over night, will act as follows: 

It will be harsh in the lathe and spoil the cutting tools. 

When hardened, it will almost certainly crack; if it does 
not crack, it will have been a remarkably good steel to begin 
with. When the temper is drawn to the proper color and the 
tap is put into use, the teeth will either crumble off or crush 
down like so much lead. 

Upon breaking the tap, the grain will be coarse and the 
steel brittle. 

To anneal any piece of steel, heat it red hot; heat it uni> 
formly and heat it through, taking care not to let the ends 
and corners get too hot. 

As soon as it is hot, take it out of the fire, the sooner the 
better, and cool it as slowly as possible. A good rule for 
heating is to heat it at so low a red that, when the piece is 
cold, it will still show the blue gloss of the oxide that was put 
there by the hammer or rolls. 

Steel annealed in this way will cut very soft; it will harden 
very hard, without cracking, and, when tempered, it will be 
very strong, nicely refined, and will hold a keen, strong edge. 



THE BURSTING AND COLLAPSING PRESSURE 
OF SOLID DRAWN TUBES. 

The following table gives the bursting and collapsing 
fMressure of solid drawn tubes: 

Bursting Collapsing 

Diameter. Pressure. Pressure. Difference. 

jX • 4800 3300 1500 

S'/s 4500 3150 1350 

3 4500 3500 1000 

2^ 5200 3500 1700 

2 j2 5000 3600 1400 

2X 5900 4500 1400 

2 5900 4900 1000 

i)^^ 5600 40CO 1600 

In this table it will be noticed that the bursting strength 
exceeds the collapsing strength, and that the diftVrence in- 
creases with the diameter, as shown in the last column. 



MINERAL WOOL. 

Mineral wool is the name of an artificial product view 
used for a great variety of pui-poses, chiefly, however, as a 
non-conductor for covering steam surfaces of whatever char- 
acter. It is largely used for this, and the underground steam 
pipes of the New York Steam Company are insulated with it. 

Mineral wool is made by converting vitreous substu.ices 
into a fibrous state. The slag of blast furnaces affords a 
large supply of material suitable for this purpose. The 
product thus obtained is known as slag wool. For the 
reason that slag is seldom free from compounds of sulphur, 
which are objectionable in the fiber, a cinder is prepared 
from which is made rock wool. These products comprise 
the two kinds of mineral wool; they are noc to be dis- 
tinguished from it, but from each other. 

The resemblance of the fibers to those of wool and 
cotton has given the names of mineral wool and silicate 
cotton to the material, but the similarity in looks is as far as 
the comparison can be followed. The hollow and joined 
structure of the organic fiber, which gives it flexibility 
and capillary properties, is wanting in the mineral fibre. 
The latter is simply finely-spun glass of irregular thickness, 
without elasticity or any such appendages as spicules, which 
would be necessary for weaving purposes. The rough sur- 
faces and markings of the fiber can only be detected under a 
strong magnifying glass. 

Aside from its uses as covering for hot surfaces, it is also 
largely employed for buildings. A filling of mineral wool in 
the ground floor, say two inches thick, protects against the 
dampness of cellar ; in the outside walls, from foundation to 
peak, between the studding, it will prevent the radiation of 
the warmth of interior, and will destroy the force of winds, 
which penetrate and cause draughts ; in the roof it will re- 
tain the heat which rises through stair-wells, bringing about 
regularity of temperature in cold weather ; the upper rooms 
will not receive the heat of the summer sun, and store it up 
for the occupants during the night, but remain as cool as 
those on the floor below ; the water fixtures in bath-rooms, 
closets and pantries will not be exposed to extremes of heat 
and cold. 

Analysis of mineral wool shows it to be a silicate of 
magnesia, lime, alumina, potash and soda. The slag-wool 
contains also some sulphur compounds. There is nothing 
organic in the material to decay or to furnish food and com* 
fort to insects and vermin ; on the other hand, the fine fibers 



220 

-ipf glass are irritating to anything which attempts to bu.row 

in them. New houses lined with mineral wool will not be- 
come infested with animal life, and old walls may be ridden 
of tbeir tenants by the introduction of it. 

Mineral wool is largely used for car linings, in which 
service it reduces the noise of travel greatly. Aside from 
those mentioned, it can be applied generally in the arts for 
all purposes where a non-conductor or a shield is required, 
and :he experience of several years show that it is both 
serviceable and cheap. 

NICKEL PLATING SOLUTION, 

, According to the Bulletin InternatioJtale de V Electricite^, 
the following solution is employed for nickel plating by sev» 
eral firms in Hainault. It is said to give a thick coating ol 
nickel firmly and rapidly deposited. The composition of the 
bath is as follows; 

Sulphate of nickel .,, « ....••,•. *». i lb. 

Neutral tartrate of ammonia 1 1 , 6 oz. 

Tannic acid with ether ., , » 08 oz. 

Water ,.......«.., 16 pints. 

The natural tartrate of ammonia is obtained by saturat- 
ing tartaric acid solution with ammonia. The nickel sul- 
phate to be added must be carefully neutralized. I'his hav- 
ing been done, the whole is dissolved in rather more than 
three pints of water, and boiled for about a quarter of an 
hour. Sufficient water is then added to make about sixteen 
pints of solution, and the whole is finally filtered. The 
deposit obtained is said to be white, soft and homogeneous. 
It has no roughness of surface, pnd will not scale off, pro- 
vided the plates have been thoroughly cleaned. By this 
method good nickel deposits can be obtained on either the 
rough or prepared casting, and at a net cost which, we are 
told, barely exceeds that of copper plating. 

HOW GAMBOGE IS PREPARED. 

Gamboge is a gum, and an average gamboge tree is said 
to yield annually sufficient to fill three bamboo cylinders, 
each about 18 to 20 inches long and i J^^ inches in diameter. 
It takes about a month to fill a cylinder. When full the 
bamboo is rotated over a fire to allow the moisture to escape 
and the gum to harden sufficiently to admit of being 
removed. 



PROOF OF THE EARTH'S MOTIOlxi. 

Any one can prove the rotary motion of the earth on its 
axis by a simple experiment. 

Take a good-sized bowl, fill it nearly full of water and 
place it upon the floor of a room which is not exposed to 
shaking or jarring from the street. 

Sprinkle over the surface of the water a coating of lyco- 
podium powder, a white substance which is sometimes used 
for the purposes of the toilet, and which can be obtained at 
almost any apothecary's. Then, upon the surface of this 
coating of powder, make with powdered charcoal a straight 
black line, say an inch or two inches in length. 

Having made this little black mark with the charcoal 
powder on the surface of the contents of the bowl, lay down 
upon the floor, close to the bowl, a stick or some other 
straight object, so that it shall be exactly parallel with a 
crack in the floor, or with any stationary object in the room 
that will serve as well. 

Leave the bowl undisturbed for a iew li ours, and then 
observe the position of the black mark with reference to the 
object it was parallel with. 

It will be found to have moved about, and tohavemoved 
from east to west, that is to say, in that direction opposite 
to that of the movement of the earth on its axis. 

The earth, in simply revolving, has carried the water and 
everything else in the bowl around with it, but the powder 
on the surface has been left behind a little. The line will 
always be found to have moved from east to west, which is 
perfectly good proof that everything else has moved the 
other way, 

WHY THE COMPASS VARIES. 

The compass, upon which the sailor has to depend, is 
subject to many eirors, the chief of which are variation and 
deviation ; that is, the magnetic needle rarely points to the 
true north, but in a direction to the right or left of north, 
according to its error at the time and place. The deviation 
of the compass comprises those errors which are local in 
their character ; that is, due to the effect of immediately 
surrounding objects, such as the magnetism of the ship itself; 
this is sometimes very great in an iron ship. 

The variation of the compass varies with the position of 
the ship, as shown by these curves of variation. Thus, from 
Cape Race to New York the variation of the compass changes 
from 30^ W. to less than 10^ W. ; and from Cape Raceto 



J^ew Orleans from 30° W. to more than 5^ E., the line of 
no variation being indicated by the heavier doub'e line 
stretchnig from the coast near Charleston down throui^h 
Puerto Rico and the Windward Islands to the northeastern 
coa'^t of South America. 

To illustrate these variation curves more clearly, a chart 
has been made upon which variation curves are plotted for 
each degree. This illustrates very strikingly the positions 
of the magnetic poles of the earth, which do not by any 
means coincide with the geographic poles. On the contrary, 
there are two northern magnetic poles and two southern; up 
';iorth of Hudson's Bay, at the point where these curves 
converge, there is one magnetic pole, and another to the 
northward of Siberia. Similarly, there are two in the south- 
ern hemisphere, and these four poles of this great magnet, 
the earth, are constantly but slowly shifting their positions, 
and just so constantly and surely does the magnetic needle 
obey these varying, but ever-present forces, seldom pointing 
toward the pole which man has marked off on his artificial 
globe, but always true to the great natural laws to which 
alone it owes allegiance. The small figures with plus and 
minus signs at various places on this chart indicate the yearly 
rate of change of variation, and this rate varies at different 
positions on the chart. Thus, near the Cape Verde Islands 
it is plus -^% ; here the variation increases ^j^ of a minute a 
year; farther to the southward, near the South American 
coast, it is plus 7^"^, and to the northward, near the Irish 
Channel, it is minus 7,-0. Fortunately, however, the^e 
changes are small and comparatively regu'ar, and iheir 
cumulative effect can be allowed for, when la.g3 enough to 
make it necessary to do so 



THE BANK OF ENGLAND DOORS. 

The Bank of England doors are now so finely balanced 
that a clerk, by pressing a knob under his desk, can close 
the outer doors instantly, and they cannot be opened again 
except by special process. This is done to prevent the 
daring and ingenious unemployed of the metropolis from 
robbing the bank. The bullion department of this and 
other banks are nightly submerged several feet in water 
by the action of machinery. In some banks the bullion 
department is connected with the manager's sleeping room, 
and an entrance cannot be effected without shooting a bolt 
in the dormitory. 



229 

KEEPING TOOLS. 

Keep your tools handy and in good condition. This applies 

everywhere and in every place, from the smallest shop to the 

greatest mechanical establishment in the world. Every tool 

should have its exact place, and should always be kept there 
when not in use. 

Having a chest or any receptacle with a lot of tools thrown 
into it promiscuously, is just as bad as putting the notes into 
an organ without regard to their proper place. If a man 
wants a wrench, chisel or hammer, it's somewhere in the box 
or chest, or somewhere else, and the search begins. Some- 
times it is found — -perhaps sharp, perhaps dull, maybe 
broken; and by the time it is found he has spent time enough 
to pay for several tools of the kind wanted. 

The habit of throwing every tool down, anyhow, and in 
any way, or any place, is one of the most detestable habits a 
man can possibly get into. It is only a matter of habit to 
correct this. Make an inflexible end of your life to " have a 
place for everything and everything in its place." 

It may take a moment more to lay a tool up carefully 
after using, but the time is more than equalized when you 
want to use it again, and so it is time saved. Habits, either 
good or bad, go a long ways in their influence on men's 
lives, and it is far better to establish and firmly maintain a 
good habit, even though that haoit has no special bearing 
on the moral character, yet all habits have their influence. 

Keeping tool? in good order, and ready to use, is as neces- 
sary as keeping them in the proper place. To take up a dull 
3aw, or a dull chisel, and try to do any kind of work with it, 
is w^orse than pulling a boat with a broom, and it all comes 
from just the same source as throwing down tools carelessly 
— habit, nothing more or less. To say you have no time to 
sharpen is worse than outright lying, for, if you have time to 
use a dull tool, you have time to put it in good order. 

AN IMPROVED SCREW-DRIVER. 
A screw-driver has been made in Philadelphia with th^ 
handle in two parts, said parts being capable of rotating one 
upon the other. A sto]:)-pin and pawl limit the movement of 
the shank in one direction, while the top of the handle will 
move backward without turning the shank. The mechanism 
appears to be very similar to the principle of a stem-winding 
watch. 



230 

THE EFFECT OF MAGNETISM ON WATCHES. 

At a meeting of the Western Railway Club, Mr. E. M. 
Herr, superintendent of telegraph of the Chicago, Burling- 
ton & Quincy Railroad, read the following paper : 

A magnet is a body, usually of steel, having the property, 
when delicately poised and free to turn, of pointing toward 
the north, and of attracting and causing to adhere to its 
ends or poles, pieces of iron, steel, and some other substances. 
Materials which are attracted by a magnet are called mag- 
netic, and it is because the rapidly moving parts of a watch 
are in general, made, in part at least, of magnetic material, 
that these timepieces are affected by that peculiar force 
magnetism. 

Were magnetic substances only affected while a magnet 
is near them, there would be little difficulty as far as 
watches are concerned. Such, unfortunately, is not the 
case, as certain materials, steel more than any other, are 
not only attracted by a magnet, but become themselves per- 
manent magnets when brought into contact with or even in 
the vicinity of a magnetized body. It is to the latter prop- 
erty of steel, namely, becoming permanently magnetized by 
the approach of a magnet without coming in contact in any 
way with it, that causes trouble with watches. 

Again, a small piece of steel is much more easily mag- 
netized than a large one; consequently, the small and deli- 
cate parts of a watch are most likely to be affected. These are 
found in the balance wheel and staff, hair spring, fork and 
escape wheel, and are the very ones in which magnetism 
causes trouble on account of the extreme accuracy and reg- 
ularity with which they must perform their movements. It 
is, in fact, upon the uniformity in the motion of the balance 
wheel, that the timekeeping qualities of the watch depend. 

In a magnetized watch this wheel, as well as all other 
steel parts, become permanent magnets, each tending to place 
itself in a north and south line, and also to attract and to be 
attracted by the others; all of which, it is hardly necessary 
to add, tends to affect its reliability as a timepiece. How 
small a variation in each vibration of the balance wheel will 
cause a serious error in the daily rate of a watch, is easily 
realized when attention is given for a moment to the number 
of double vibrations this wheel makes in 24 hours. 

This varies in different watches from 174,000 to 216,000, 
and the variation of a single vibration in this number will 
cause a greater error than is sometimes found in the best 
watch movements. It is therefore true that the variation in 



231 

each vibration of the balance wheel of 1-200,000 part of 
thetimeof such vibration^ or in actual time about the 1-500,- 
000 part of a second, will prevent the watch rating as a 
strictly first-class time piece. 

I wish to state, however, that there are very few watches 
made of ordinary materials which are absolutely free from 
magnetism. This may seem like a sweeping statement, but, 
after taking considerable pains to verify or disprove of it, I 
am convinced that it is substantially correct. 

Why this should be so becomes evident when we consider 
that a few sharp blows upon a piece of steel held in the di- 
rection of a dipping needle suffice to sensibly magnetize it, and 
then think of the numerous mechanical operations that have 
to be performed upon each small piece of steel in the moving 
parts of a watch before it becomes a finished product. 

In order to determine, if possible, to what extent 
magnetism prevails in watches, I have examined and tested 
for magnetism 28 watches carried by persons other than train 
or engineer men, with the following result : Three were very 
seriously magnetized ; one to such an extent that it could not 
be regulated closely ; twenty barely perceptil^ly affected, 
possibly, but the normal amount due to the process of 
manufacture, and in but four could no magnetism be 
detected. 

On account of the steel parts of a locomotive being 
magnetized during the process of construction, and by severe 
usage in a similar manner to those of a watch, it has been 
claimed that the watches of engineers are constantly subjected 
to the action of the magnetic forces, and cannot therefore 
keep as good time as other watches. 

I have examined for magnetism the different parts of a 
number of locomotives in actual service, and, although they 
were in general found to be magnetic, they are so slightly 
charged as to render it almost certain they could have no 
influence upon the rate of a watch, and would surely produce 
less effect upon it than the originally slightly magnetized 
parts of the watch itself. That this amounts to practically 
nothing, is proven by the large number of finely rated 
watches now in use in which magnetism is apparent. 

As proof of the statement that engine-men's watches are 
not, as a rule, more highly charged with magnetism than 
those of men engaged in other occupations, the watches of 
twenty locomotive engineers were tested. Of these none 
were found heavily charged with magnetism; but *^^wo more 
than normal; twelve with a barely perceptible charge, and 
in six none could be detected, showing actpally less magnet- 



232 

ism in these than in the twenty-eight watches previously 
examined, none of which were carried on a locomotive, a 
result probably due to the fact that engineers, as a rule, are 
very careful of their watches, and are less apt to bring them 
in dangerous proximity to a dynaiiio than those not con- 
cerned in running trains, and in whom a well-regulated watch 
is less important. This, I take it, w^ould surely be the case 
did they all understand that a watch is likely to be entirely 
disabled by bringing it near a dynamo or motor in opera- 
tion. It therefore seems important that all to whom accu- 
rate time is a necessity, should be carefully instructed as to 
where the danger lies. 

So much has recently been written about the magnetiz- 
ing of watches that many persons approach any kind of elec- 
trical apparatus with caution. Even a battery of ordinary 
gravity, or LeClanche cells, is regarded with suspicion, 
while a storage battery is thought almost as dangerous as a 
dynamo. 

Others, on the other hand, do not even know that a 
dynamo is dangerous to watches. It should be borne in 
mind that it is not electricity which affects watches, but 
magnetism, and that magnets are the seats of danger. It is 
the powerful electro-magnets in dynamos and motors that 
magnetize watches, and not the strong currents of electricity 
generated or consumed by them. True, there is a mag- 
netic field about every current of electricity, but it is so 
very slight that no effect is produced on watches worn in the 
pocket. 

Having spoken of the evils of magnetism in watches, it 
is, perhaps, proper to add a few words regarding its preven- 
tion. The best and most certain way to prevent a watch 
becoming magnetized is to never allow it to come near a 
magnet, Unfortunately, in the present age, this is a diffi- 
cult matter, as no one can say how soon they may find it 
necessary to be in the vicinity of a dynamo in operation or 
be seated in a car propelled by an electro-motor. 

The only practical protection to watches from magnetism 
of which I have been able to learn consists essentially of a 
cup-like casing of very pure soft iron surrounding the works 
of the watch, which is known as the anti-magnetic shield. 
That this device is a protection from the effects of magnet- 
ism upon watches, there can be no doubt, but that it pre- 
vents magnetizing under all circumstances, even its inventor, 
I believe, does not claim. 

^■) It therefore becomes important to know how far our 
watches are safe when supplied with this protection, and 



233 

where to draw the danger line for the protected, as well as 
the unprotected watch. In order to throw some light upon 
this question, the following tests were made: 

First, to discover to what extent magnetic bodies placed 
within the shield were protected from external magnetic 
forces ; second, in how strong a magnetic field it was neces- 
sary to place a watch protected by this device to effect its 
rate by magnetization. 

While no pretense of scientific accuracy or precision was 
made in these tests, it is believed they are sufficiently accu- 
rate for scientific purposes. 

The first test was made by filling an inverted shield half 
full of water, on the surface of which a very light magnetized 
steel needle was caused to float. In a similarly shaped cup, 
made of porcelain, another needle, in all respects like the 
first, was also floated. A horseshoe magnet was then 
brought near each, and found to affect each needle equally, 
at the following distances : in shield, 6 in. ; in porcelain cup, 
l^yz in. 

Distance below a ^-m. wooden board, upon which shield 
and cup were placed, at which needles could be just reversed 
by magnet — in shield, 33^ in. ; in porcelain cup, SX in. 
With just enough water to cover the bottom of shield, the 
following distances for equal effects were observed : first 
exposure in shield, 8 in. : first exposure in porcelain cup, 
20 in. ; second exposure in shield, 12 in. : second exposure 
in porcelain cup, 30 inches. 

Since the intensity' of a magnetic force varies inversely as 
the square of the distance, the above results indicate that to 
produce like effects, at equal distances, magnetic forces from 
five to six times as strong would be required, with bodies 
inclosed within the shield, than with those not so protected. 

|The second test was made with watches of different 
makes, all furnished with the shield. Space will not permit 
my going into the details of these tests, which extended over 
several months. I will only say that they in general con- 
sisted in obtaining the rating and performance of the watch 
before and after it was exposed to magnetic influences, The 
exposure consisted in placing it nearer and nearer to the pole 
pieces of a powerful arc light dynamo and observing the 
rate before and after each exposure. After many tests of 
this kind, the conclusion was reached that a watch carefully 
and properly shielded could be safely placed not nearer than 
4 in. to the pole pieces of a 20 arc light Ball dynamo. 
When brought nearer they were without exception magnet- 



234 

ized to a greater or less degree, the amount depending 
largely upon the time of such exposure. 

Watches are now being made, however, which it is 
claimed are entirely non-magnetic and unaffected by the 
strongest magnetic fields met with in practice. Several 
such watches were also examined and tested. They were 
furnished with a balance-wheel, hair-spring, fork and escape 
wheel made of an alloy of non-magnetic metals in which 
palladium is the principal component. The first of these 
watches tested was furnished only with a non-magnetic bal- 
ance and hair-spring, and had a steel fork and escape wheel. 
This watch is instantly stopped when brought near a power- 
ful dynamo. 

Olher movements were then tried, in which all of the 
rapidly moving parts were of non-magnetic material. These 
could not be stopped by the field magnets of the most 
powerful arc light dynamos, although when placed in actual 
contact with the pole piece the balance-wbeel was seen to 
vibrate less freely, probably due to the attraction of the 
staff and pivots, vvhich were of steel. The rate of the 
watch was not, however, altered by this test. 

A hair-spring made of this non-magnetic alloy was also 
drUcately suspended in still air and subjected to the action 
of a powerful horseshoe magnet without developing the 
slightest observable magnetic effect. 

One of our best-known American watch manufacturing 
firms is now making a non-magnetic watch on a plan similar 
to that just described ; others will probably soon follow, 
hastening the day when a watch thoroughly protected or 
inherently insensible to magnetism will be as common, and 
considered as necessary to the successful keeping of correct 
time as "he adjustment for temperature and position is 
already. 

HOW BARRELS ARE MADE. 

Barrels are now being made of hard and soft wood, each 
alternate stave being of the soft variety, and slightly thicker 
than the hard-wood stave. The edges of the staves are cut 
square, and, when placed together to form the barrel, the out- 
sides are even, and there is a V-shaped crack between each 
stave from top to bottom. In this arrangement the operation 
of driving the hoops forces the edges of the hard stave into 
the soft ones, until the cracks are closed, and the extra thick- 
ness of the latter causes the inner edges to lap over those of 
of the hard-wood staves, thus making the joints doubly 
secure. 



235 

FACTS ABOUT IRON CASTINGS. 

Some experience of the changes of shape which castings 
undergo by reason of shrinkage strains is necessary, in order 
to proportion them correctly. I have seen numerous massive 
and very strong looking castings fracture during cooling, or a 
long time afterward while lying in the yard untouched, or 
while being machined ; the reason being that excessive con- 
traction in one portion had put adjacent parts into a condition 
of great tension. By putting an excess of metal into some 
vulnerable point of a casting, is introduced an element of 
weakness, and almost a certamty of its breaking by reason of 
the internal shrinkage strains. It is not the excess of metal 
in itself which gives rise to these strains, but the position in 
which it is placed relatively to other sections. Thus a lump 
of metal cast in juxtaposition to a thinner portion will not 
break the latter, so long as it is able to shrink freely upon 
itself. Bat if placed between two thinner portions, it may 
fracture them by its shrinkage. Hence the great aim is to so 
design castings that all portions thereof thall cool down with 
approximate uniformity. A founder learns much from the 
behavior of case-iron pulleys and light wheels. As they are 
so light and weak, proportioning must be correctly observed, 
and when customers ask for a " good, strong boss " or " strong 
arms," the request is one which, if complied with in the 
manner described ; that is, by unduly increasing the metal, 
will either fracture the pulley or wheel, or bring it near 
to breaking limit. In all castings "strong" is a relative 
term, that form or size being strongest which harmonizes 
as regards general proportions. In a light pulley, three 
different conditions may exist: i. All parts may cool 
down alike, or nearly so ; 2. The rim may cool long before 
the arms and boss; 3. The arms and boss inay cool before 
the rim. ±n the first case, the pulley will be strong and safe. 
In the second, the rim, in cooling, will set rigidly, but the 
arms and boss will continue shrinking, each arm exerting an 
inward pull on the rim, and various results may follow. 
First, the strain may simply cause the arm to straighten; 
or, in less favorable conditions, and especially if straight 
arms, or arms but slightly curved, be used, the arms may 
fracture near the rim, but seldom near the boss. Or, if the 
rim be weaker than the arm, fracture will take place, or the 
pulley may be turned, and then break. ^ In the thinl cas;:, the 
arms and boss cooling before the rim, they are compresse 1 
by the shrinkage of the latter, and the arms may then b HM»me 
fractured, if curved; or, if straight, may prevent the rim from 



236 

coming inward, and so break it. In most cases, fracture 
occurs from the mass of metal in the boss. As a single instruct- 
tive example out of many, I may quote that of a pair of 
2 ft. 6 in. pulleys, fast and loose, which had been running for 
several years, the fast pulley had a boss 6 in. in diameter, the 
loose pulley one of 5 in. only, and both were bored to 3 in. 
By the accidental falling of a bar of iron, both were broken. 
The rim of the fast pulley was at once pulled in, while the 
loose pulley rem.ained level at the point of fracture. This 
illustrates the presence of tension in the rim, due to the 
larger boss, and this tension had been present since the pulley 
was made. The pulley with the 5 in. boss wa^ probably 
much stronger than that with the six in. boss. In fast pul- 
leys, and in wheels keyed on, the necessary strength around 
the key way may be obtained by the use of key way bosses, 
without increasing the entire diameter Where large bosses 
are unavoidable, as in some deep, double-armed pulleys, or 
in spur wheels keyed onto large shafts, shrinkage is assisted 
by opening out the mold around the bosses, and removing 
the central core, thereby accelerating the radiation of heat, 
and further by cooling them with water from a swab brush 
when at a low red or black heat. Many a casting is saved 
in this way Another method is to split the boss with plates, 
and bond or bolt it together afterward. When casting fly- 
wheels with wrought-iron arms, the rim is first cast around 
the arms and allowed to cool nearly down before the boss is 
poured. If the latter were cast at the same time as the rim, 
it would set first, and, by preventing the arms from coming 
inward, would put tension upon the rim. 

Whe^e aggregations of metal occur in castings, they may, 
if the castings be too strong to fracture, cause an evil of 
a secondary character, known as " drawing;" in other words, 
the metal is put into a condition of internal stress, and 
becomes open and spongy in consequence. " Feeding " tends 
to diminish this evil; but m.uch can often be done by light- 
ening the metal with cores, chambering out, or reducing the 
metal massed in certain places by other means. There is a 
difference in the behavior of cast-iron and of gun metal, of 
which advantage may be taken in small, light castings. 
Designs which will not stand in cast-iron or steel will stand 
n gun metal, hence the latter may be useful in cases of diffi- 
culty. 

Sharp angles very often lead to fracture. When brackets, 
ribs, slugs, etc. , are cast on work, the corners should never 
be left square or angular, for, if there be much disproportion 



237 

of metal, fracture will almost certainly commence in the 
angles. 

I have already alluded to the " straining " which large 
plated and heavy castings undergo, so that the sides and 
faces increase in dimensions, becoming more or less rounded. 
The main reason is, I think, that the metal round the 
central portions does not cool so rapidly as that at the 
sides. The outsidss radiate heat quickly, and shrink to 
their full extent; but the middle rib or ribs, and the cen- 
tral portions of the plate, retain their heat longer, and 
hold the sides in a condition of tension, thus forcing them to 
bulge or become round. When the central portions cool, 
the outsides are too rigid to yield to the inward pull. This 
refers to framed hollow work. When plates " gather " or 
increase in thickness, it is due mainly to the lifting of the 
cope, from insufficient weighting. When a cubical mass of 
metal shows no shrinkage, this is due to the pressure of the 
entire mass compressing the sand on every side. 

Briefly stated, then, in deciding the proper contraction 
allowance for a pattern, I should take into consideration its 
mass, the manner in which it is molded and cast, the Dresence 
or absence of cores, and the nature of the same, its general 
outline, and the character of the metal. For a heavy solia 
casting in iron, I should allow considerably less than t'? 
normal contraction for iron ; for a similar casting in steel, 
more than the normal contraction for steel; for a heavy 
casting in gun metal, less than the normal contraction foi 
gun metal. The precise allowance in any case must be 
regulated by circumstances. For the vertical depth of a 
shallow casting, very little shrinkage, if any, should be 
allowed; for a deep casting, the full amount. Then, again, 
a mold, with dry sand cores of moderate or large size, will 
not allow the casting to shrink so much as if the cores were 
of green sand, or were altogether absent. For hard and 
chilled iron, the shrinkage will be at its maximum ; for 
strong mottled iron, at its maximum ; and for common gray 
metal, at about the average. 

FLEXIBLE GLASS. 

An article called flexible glass is now made by soaking 
paper of proper thickness in copal varnish, thus making it 
transparent, polishing it when dry, and rubbing it wilh pumice 
stone. A layer of soluble glass is then njipl-ed nndiubbfd 
with salt. The surface tiius produced is said lo be as perfect 
<ls ordinary irlpss 



23^ 

COMMON NAMES OP CHEMICAL SUBSTANCES 

Aqua Foriis Nitric Acid 

Aqua Regia Nilro- Muriatic Acid 

Blue Vitriol Sulphate of Copper 

Cream of Tartar Bitartrate of Potassium 

Calomel Chloride of Mercury- 
Chalk Carbonate of Calcium 

Salt of Tartar Carbonate of Potassa 

Caustic Potassa Hydrate of Potassium 

Chloroform Chloride of C orm.yle 

Common Salt Chloride of Sodium 

Copperas or Green VitriolSulphate of Iron 

Corrosive Sublimate Bichloride of Mercury 

Diamond Pure Carbon 

Dry Alum Sulphate Aluminum and Potassium 

Epsom Salts Sulphate of Magnesia 

Ethiops Mineral Black Sulphide of Mercury 

Fire Damp Light Carbureted Hydrogen 

Galena Sulphide of Lead 

Glucose Grape Sugar 

Goulard Water Basic Acetate of Lead 

Iron Pyrites Bisulphide of Iron 

Jeweler's Putty. Oxide of Tin 

King Yellow Sulphide of Arsenic 

Laughing Gas ... Protoxide of Nitrogen 

Lime Oxide of Calcium 

Lunar Caustic Nitrate of Silver 

Mosaic Gold Bisulphide of Tin 

Muriate of Lime Chloride of Calcium 

Niter of Saltpeter Nitrate of Potash 

Oil of Vitriol Sulphuric Acid 

Potash ' - Oxide of Potassium 

Red Lead Oxide of Lead 

Rust of Iron .' Oxide of Iron 

Sal Ammoniac Muriate of Ammonia 

Slacked Lime Hydrate of Calcium 

Soda Oxide of Sodium 

Spirits of Hartshorn. . . . Ammonia 

Spirit of Salt Hydrochloric or Muriatic Acid 

Stucco, or Plaster Paris.. Sulphate of Lime 

Sugar of Lead Acetate of Lead 

Vgrdigris Basic Acetate of Copper 

Vermilion Sulphide of Mercury 

Vinegar Acetic Acid (diluted 

Volatile Alkali Ammonia 

Water Oxide of Hydrogen 

White Precipitate Ammoniated Mercury 

White Vitriol Sulphate of Zinc 

TO CLEAN RUSTY STEEL. 

Mix ten parts of tin putty, eight parts of prepared buck's 
horn, and twenty-five parts of spirit of wine to a paste. 
Cleanse the steel with this preparation, and finally rub off 
with soft blotting paper. 



239 

HINTS ON PATTERN-MAKING. 

The pattern shop is one of the most important depart- 
ments in a plant for the manufacture of machinery. It is 
here that the plans of the mechanical engineer are first 
developed, and upon the skillful manner in which the pat- 
terns are constructed and those plans faithfully carried out, 
depends much of the future success in the manufacture of the 
machine. The skillful pattern-maker, by accurate calcula- 
tions for shrinkage, finishing and the contingencies of the 
foundry, may save a great amount of labor and annoyance in 
the machine shop. It is unreasonable to expect perfect cast- 
ings from imperfect patterns, and the molder is often blamed 
for imperfections of the castings when the fault may be traced 
to an imperfect pattern. Holders as a class have sins 
enough of their own to answer for without the addition of 
the sins of the pattern-maker. Patterns are as a rule neces- 
sarily expensive, and should be carefully constructed, so that 
they will retain their shape and proportions for future use, 
and to this end the selection of materials and the manner of 
joining the several parts together becomes an important item. 
For all ordinary purposes, especially for patterns of consider- 
able size, good, clear, well-seasoned white pine is the best, 
and to obtain the best results it should be seasoned in the 
open air in the natural way. The sap of all the woods con- 
tains a large percentage of water, and to get rid of 
this is the object in seasoning. Pine wood, besides 
water, contains a large percentage of turpentine in 
the sap, and in seasoning it, it is desirable to retain 
as much of this as possible, as it dries to a hard substance 
when seasoned in the open air, and helps in a measure to fill 
up the pores of the wood, and renders it close and more 
impervious to water, and less liable to be affected by damp- 
ness. Kiln-dried lumber, although extensively used at the 
present time, is not as good for this purpose. The heat and 
moisture used for this purpose expels, not only the water, 
but other ingredients, which leaves the grain open and brash, 
and patterns made from such materials are more liable to 
absorb dampness and warp than otherwise. In constructing 
patterns, especially those of considerable size, it is cus- 
comary to build them up of several pieces glued together; 
this makes more reliable work, provided good glue is used 
and proper care manifested in the manner of putting 
them together. No two pieces should be glued together 
with grain crossing at right angles, for, no matter how dry 
the lumber may be, there will always be some shrinkage. 



240 

and, as lumber shrinks, almost entirely, in its transverse sec- 
tion, it is sure to warp, unless the glue gives way so as to 
allow each part to shrink in its natural direction. In either 
case the pattern will be unfit for further use until it is 
repaired. It is not good practice either, to glue up stuff for 
patterns with the grain of each piece running parallel with 
the other, as such patterns are deficient in strength, and are 
liable to split. The most practical way is to arrange the 
several pieces so that, when put together, the grain will run 
diagonally across each piece, at an angle of about twenty- 
five or thirty degrees. Pattern stuff prepared in this man- 
ner will have sufficient strength to prevent splitting by use 
and handling, and the tendency for warping will, to a great 
extent, be avoided. In building up circles, the cants should 
be short, and cut lengthwise of the grain as far as possible, 
so that the grain of each course as it is laid together to 
break points, may cross each other diagonally. It is cus- 
tomary with some pattern-makers to use nails or birds in 
each course as it is laid up, but pegs made of maple 
or hickory are much better, and, when the stuff is suffi- 
ciently thin to admit of it, the common pegs used in shoe 
shops are very cheap and convenient. The advantage of 
using pegs instead of brads or nails is, that, being driven 
in glue, they hold better, and the cants are not as liable to 
spring apart when exposed to the warm, damp sand in the 
foundry; besides, they never give the workman any trouble 
when turning it; and experience has demonstrated that pat- 
terns put together in this manner are much more durable 
than otherwise. Some pattern-makers use but little judg- 
ment in the use of glue, and seem to have an idea that the 
more glue they can get between two surfaces the better; yet, 
every experienced mechanic knows that exactly the reverse 
is the case. With a good joint and clear, fresh, thin glue, 
the least that is retained between the two surfaces the bet- 
ter and stronger will be the joint. In hot weather glue soon 
sours, turns black and becomes rancid; when in this condi- 
tion, its strength is impaired and it is unfit for use. Alco- 
hol mixed with it will prevent souring, but, as soon as it is 
healed up, the alcohol evaporates, and its effects are lost. 
The most effective preventive is sulphuric acid, but the 
acid should not be applied clear. For an ordinary glue-pet 
about fifteen drops of the acid mixed with a couple of 
spoonfuls of water may be applied; while this in no way 
impairs the strength of the glue, it will effectually prevent 
souring, and keep it fresh and clear. 

tor small gear patterns that are to be in constant use, cut 



241 

patterns of iron or brass are no doubt the best and cheapest 
in the end; but, if wood patterns are required, they should be 
made of some harder wood than pine ; mahogany or cherry 
is considered the best for such work. After the hub is turned 
to the proper size and width of face, the blanks for the teeth 
may be glued on and dressed in their places. With large, 
wide-faced gears, it is not convenient to do so ; the blanks 
for the cogs are usually glued to dovetailed slips, or the 
dovetailed formed on the under side of the blank so that, 
when fitted to the rim, or dressed off, and laid out, they maiJ 
be removed for the convenience of finishing them. The 
dove-tails should be a perfect fit, and the blank well fitted 
to the rim; otherwise they will vary the pitch when dressed 
and replaced again. In constructing patterns for heavy 
castings, such as lathe and engine beds, the careful and evei? 
distribution of metal in each part is an important considera* 
tion, and, in order to give some particular part the requisite 
strength to withstand a heavy strain, it is sometimes necessary 
to put more metal in some other part where it is not needed 
in order to prevent the casting from being distorted in shape 
or cracked by the unequal construction caused by one part 
cooling faster than another, "With the framework for lighter 
machinery the same alio wane t for shrinkage must be provided 
for. But where a frame is composed of several parts, some 
of which are much lighter than others and yet it is necessary 
that the whole should be cast together, it is well to make 
the lighter portions in curves as far as the nature of the work 
will permit. Sharp edges and square corners should also be 
avoided as far as possible. A small cove in each corner will 
add much to the convenience of molding, besides adding to 
the strength of the casting and insure it against cracks, which 
are liable to open at these points by shrinkage in cooling. 

The pattern-maker should also exercise good judgment 
in making provision for withdrawing the pattern from the 
sand; but, as no two patterns are just alike in this respect, no 
definite rule can be followed. In intricate patterns, which 
require considerable skill and care on the part of the molder 
in withdrawing them from the sand, if the nature of the 
work will admit of it, considerable more draft should be 
jillowed for this reason. But plain patterns may be nearly 
straight, provided their surface is perfectly smooth. For 
much draft, especially with gearing, is very objectionable, 
for it is impossible for such gearing to run together 
accurately, and bear the whole length of the tooth or 
cog, unl'^ss they are either chipped and filled, £>r planed 
Straight. If gear patterns are made accurate and true. 



^4^ 

and the face of the cogs perfectly smooth, there will be 
no difficulty in molding them if they are nearly or quite 
Straight. All patterns before being used should be well 
covered with at least two coats of pure shellac varnish. 
After applying the first coat, and when it is perfectly dry, 
the surface should be well rubbed down with fine sandpaper, 
and all imperfections, such as nail holes and sharp corners, 
not already provided for, should be carefully filled with bees- 
wax and rubbed off smooth before the second coat of var- 
nish is applied. After a pattern has once been used, it is 
good practice to again rub it off with very fine sandpaper, 
and apply another coat of varnish. Many well-made pat- 
terns are ruined in the foundry by not being provided with 
the proper facilities for rapping and drawing. The molder 
must have some means for attaching his appliances for lift- 
ing it out, and, if suitable provision is not made for this pur- 
pose, he will screw his lifter in any part of the pattern tha^ 
is most convenient, and the chances are, that it will split the 
first time it is used, or badly marred up. Iron plates should 
be let into all patterns with holes threaded to suit his lifters, 
and well secured either by screws or rivets, and, if a sufficient 
number are attached, the molder will respect the pattern and 
use them. Wood patterns should never be allowed tc 
remain in the foundry; as soon as they are used, they should 
be taken to the pattern-room, brushed off ana placed in such 
a position for future use that they will not become warped 
or sprung. 

ELECTRIC HAND LANTERN. 

A German patent has been granted to A. Friedlander 
for an electric hand lantern. This consists of a box of hard 
rubber carrying a small three-candle power incandescent 
light, together with a reflector and glass protector. The 
elements in the box, carbon and zinc, produce the current 
necessary to feed the light. The box is divided into five 
compartments holding the liquid, and the electrodes are 
placed in such position that no decomposition occurs when 
the lantern is not in use. The circuit is closed when the 
electrodes are dipped in the liquid ; the current is stronger 
and the liq;ht brighter if the electrodes are dipped deeper in 
the liquid ; this depth and consequentlv the brightness of the 
light can be regulated by means of a button on the outside. 
The liquid is a combined solution of chloride of zinc, bichro- 
mate of soda in water and acid, and the lantern can hold a 
sufficient supply of lli.s solution to last for about three hours. 



^43 

rABLES OF GEARS FOR CUTTING STANDaRI^ 
SCREW-THREADS. 

INTRODUCTION. 

It may, perhaps, be necessary to state that these tables 
are the fruit of much experience, and a deep-seated convic« 
tion that their want is sorely felt by many. Notwithstanding 
the vast improvements of modern screw-cuttini^ machinery, 
much time is still wasted by the most experienced workmen 
in endeavoring to find wheels to but any particular pitch o. 
screw, or broken number, in consequence of the various 
changes to be obtained from the usual set of screw-cutting 
wheels, most of which begin with a 20-teeth, 25, 30, 35, 40, 
45» 5O' 55» 60, 65, 70, 75, 80, 85, 90, 95, 100, no, 120, 130, 
140 and 150. This may be considered a full set, inasmuch as 
any screw may be cut with it, Supposing the 20-wheel to 
be put on the mandrel, for single changes, without the pinion, 
the first figure up to 95 will give the number of threads to 
the inch. A 20 and A 25 will cut 2J4 ; 20 and 30, 3 to the 
inch, and so on in like ratio. When three figures are on the 
wheels, however, the first two will indicate the number to 
the inch ; as, 20 and 100 will cut 10 ; 20 and 1 10 will cut 11; 
etc. For many common numbers this will save the trouble 
of looking to the tables, if a ^, ^, or other coarse pitch. 
If the. book be referred to for the decimal of the ratios 
required, against it will be found the wheels that will cat it. 
If the number be required to the foot, then multiply by twelve. 

These tables are calculated on the assumption that a pin- 
ion of twenty teeth is used, and a driving-screw of two 
threads to the inch. 

Wheels, when affixed to the mandrel, are r ^.hod maadrel* 
wheels ; those on the screw, screw-wheels ; aj d those inter- 
vening, intermediate-wheels. When the ma/ drel and screw- 
wheels are connected by one or more whe is directly, they 
are termed simple wheels. When attach/? i by means of a 
pinion joined to the intermediate wheel iwey are calledcom- 
pound-wheels. 

'^o. I, is a table of sirwpi*; wiieels. The mandrel- wheels 
are in the first perpendicular column; and the screw-wheels 
in the top horizontal column. In the spaces where the per- 
pendicular intersects the horizontal, will be fovmd the pitch of 
the thread which any two wheels will cut. 

The remaining tables are of compound wheels. The 
mandrel-whee's will be fojnd in the first ]:)erpendicular column, 
the intermediate-wheels in the top horizontal column, and 
the screw-wheels in the bottom column. The pitch of thread 



244 

to be cut having been found in the tables, on the left hand 
the mandrel- wheel will be found, on the top the intermediate 
wheel, and at the bottom the screw-wheel. 

All lathes have not a twenty-teeth pinion, in which case, 
the following rule will be of use as applying to any other 
pinion : 

Multiply the pitch of thread intended to be cut, by the 
new pinion, and divide by twenty. Find the wheels in the 
tables corresponding with the quotient, and use the new pin- 
ion instead of the twenty. 

In some lathes the mandrel-w^heel is a fixture. In these 
instances, suppose the mandrel-wheel to be the pinion, and 
attach the mandrel- wheel found in the t;',ble to the interme- 
diate-wheel. 

To ascertain the ratio of any series of wheels, multiply 
the whole of the driven wheels togetner, which will give the 
total number of teeth in the series. Then divide the result 
by the driving wheels multiplied into each other. The quo- 
tient will be the number of times the first wheel will revolve 
to the last. Suppose a wheel of twentv teeth to be driving 
a wheel of loo teeth, to which is attached a wheel of thirty 
teeth driving a wheel of 150 teeth, and the ratio be reoiured — 
100 X 150 

■ =25 revolutions. 

20 X 30 

To find the number of threads a set of wheels will cut, multiply the 
ratio of the wheels by the pitch of the driving-screw. 

To cut double or more threads, divide the mandrel-wheel in as 
many parts as you require threads, and, as you cut the screw, shift the 
mandrel-wheel a division, while the screw-wheel remains stationary. 
This plan will insure equal division and regularity of cutting. In all 
lathes where the leading screw is two to the inch, and an equal number 
of threads being cut, if the saddled clutch be thrown out of gear, it will 
always fall into the right place. If an odd number of threads are bemg 
cut, it will fall right every other one. By rittending to this rule, run- 
nmg the latrie backward will be avoided, and a screw cut in about half 
the time. 

A difficulty frequently arises in finding the number of threads to the 
ik-ch or foot when a particular pitch or fractional number has to be 
matched. This can easily be ascertained by measuring onward, for, if 
it do not come right in one Inch, notice how msny there are betweei: 
any division of rule. In measuring a screw, you discover there are 
twenty-eight threads in three Inches. Consequently, If twenty-eight be 
divided by three, it gives 9.333 as the pitch. Against that number in 
the table will be found the wheels to cut it. Suppose a coarse pitch be 
required, say one thread In i;^ inch, the wheels may be found thus: 
when there is less than one thread to the Inch, see how many there are 
in twelve inches; as, 1.615 In. pitch into 12 in. Is 7.384 to the foot. If 
divided by twelve, we have the dec, 615, against which in the tabic 
will be found the wheels. 



245 



u 



00 lo ro 



N O ■<*• 

^N 10 ro M 



xfi rhvo a\ f^ fO M 
t^vO *0 t>. VO 'iJ^ 10 N. 
00 t^vO 10 »o ro N M © 



t^VO lO"*nfOfON « W N N 



Tj- CO 10 m w osvo -"i- N M 
oo^OlOT^'<l-fOfON c; m m n n 



OJt>»Th Tl-roON'O 
00 c^oo in ro m ■"^•"O 
00 c^vo vo "^ m w M o 



vo t^ t^ H m inoo >o in 
vommt-^ c^iroHNvocN 

inOO VOOO CM t^-'^OOO'O Tj-M H 



00 o\ invo t^ Th 
00 00 T^ w o >-i 
00 c^ tx in -* ro 0) 



oovoinrf-'>*-rororrN « o) « w m 



On H t^ 
vo t>. in H 
t^ in -^ (N M 



-^ vo Th in 
0\ ro 00 00 
00 00 vo in ro N N 



ON t^vo in-*-<i-rOrOmWN(NN(N(NHHMHHMM 



moo M Tf-vo ro ->*• (D in in H 

ro N in (N invo (n h ro t^ ro m 

rnvo ^OT^t>N0O ->^h ONt-Ninrow h 



t^ ro M t^vo 

(N 00 "O mvo 

On t^ m -"^ ro CM 



On t^vo m'^'tt-rororoNCMMNrowNi-.HMHH 



vo ro t^ t>«>o roNin ooMDooooro 
ro ro t^ rnvo mwO M^oroMro 
voroOooNomroNM co^m-^ro 



OoovominTh^rororoc^j (n cm pj C4 cm cm m 






00 


rOTh 00 NO-^fgro 00 -^VD 
rooo 00 NO c» -^ r^-) moo ■^ « 
ro M moo ■<*• voroMO\r^m-<i-rocM 


ro CM M vO 
ro C3N t^NO 
00 NO m -^ 




H 00 

H 


t^No m-^'^'<4-rororoM cm c<) c) cm cm cm 


H H H H 




cm 


VO 


VO ro ro CM 00 roNO vc h 
mrovo oncm cmnoo 00 
00 rooo ro vo-^(N ooNom-<*-M 


VO T^ 
00 ttvo 


Ht 


CM c^oo NOVO in-<*-'^-<i-rorororoM cm cm cm cm 


CM H H M 



VO 00 t^ t-^ ro 

VO N r^ CM ro 

•<4-vo T^ m t^ CM t^ ro 



Tj-vo 00 00 NO rovo t^ ro 
H NO m moo ro no no m ro 
t^ ^ CM o 00 r--NO 00 M 00 c>. 



ro O 00 t^vo mm^rf-<*-rorororocM (n cm cm n n m m 



CM NO t^ 

CM ONO O 

CM NO O NO ro 



ro Tt- w r^ 

ro CJn H --^ . . 

t^ m CM w CJnoo m ro 



m ro ro vO 

ro m VO 

CO 



Onco t^vo mm->4-'<j-'>frorororoCM cm cm cm cm cm 



H NO 

r>. NO 

m inNO 



m m 
M 00 
VO cm 



On ro t^ r^ t^ cm 
m CM ro m c^ O -^ 
t^rnrOH t^mroM 



m CM o 00 t^No NO m m ""i- 



rororoooroN N N N CM 



•siaaHAv aanaNviM 



246 






** C9.'5^ '^'^ "*>0P ^^ ♦^O ^^««l I 
^ CO ws 



^ CO H (vj !>. lovo M in woo 

t% m CO N o o\oo cx) i^ t^vo vo vo m to ^ ^ T^ 



t^ 10 -^ N H O 



onoo 00 t^ o. t^vo 10 tn m 



CO N N N 



vo 00 i~^ m ro on -^sO 
W vo oj c^vo -^ rn M H o 



M 00 <M t*.VO m M fO 

Thoo "^^ o vo H t^ CO 

O^OO 00 00 t>sVO O »0 IT) 



•^ fO N (N W 



in 00 

(N 10 

M O 



t^ 00 « « 

■<*■ -1 10 On ■* 
O^ Onoo t^vo vo vO 



■* ro fo N « w 



mm N 
mcx3 10 N 



00 vo 00 00 m vo 
M vo m (N m m t>i 
00 vo 10 ■<*- m N M 



0\ m o\ rt-\o 
O rovo M vo 
ONOO t^ t^vo 



»0 -"i- m N M W N 



vo N "* 

vo Tf 10 ■<l^ 
m "^vo H t>s Tj- N 



mNMVoin-^Nm vovovnro 

m o\ t^vo o^ o> (N vo M ^00 rn 

oovo lO-^mN N M M onoo t^ t^ 



lo-^fomw N N M 



vS 



vo m vot}- wrom M mt>. 

vo 00 •«*• w M mvo o\ N in 

vo Tj- M 00 t^vo in -<*• m 01 w o Ovoo 00 



vo^-<*-rnrONONW 



CO -<*• 00 mvo 

m p- inoo vo vo 

ION m^s^^oovo n-jM 



t-^miooN^oo Mco oovo 
in m w CN -"J-vo 00 00 w vo 
00 r^vo m Tj- m m M o o^oo 



vom-^mmc^ w n n cs 



vo 

vo 

vo vo 



inmm vo t^inrn nvovo m 
-^mm voinmmr>. r^vo t^ m 
in m iH 00 t^vo m -^ -^ w M o 0\ 



t>.iO'*'^mmw w M 01 N 



^O»o0io0 if\ ^ ^ V) 
c* CO m ■>;»• "^ 10 lovo 'O t^ t^oo 00 



•ST3aHA\ aa^QNVlM 



PINION 20. 



s 




h* CO N VO 00 t>>VO ON VO 

10 ro t^ tN N 10 -^vo 00 ro 
00 10 ro w -^ t^vo VO vc 


00 ■* 
ko in t>* 




Kv8 


N t^roo t^ioroMOoo t-^vo in m ro 


<N M 

M H M 


2 


CO 


H ro iri (N VO 0\ 
t«H n rf rooo U-) invo 00 N 


rooo 
H -^ 


e 


M 


VO N •^ r>% ro c^ivo •* N 00 t-'-'O 10 -"^ c^. ro N 

VOlOTj-rOrOPlWCMWNl-lHMMMWHH 


M 0\ 

H HI 


M 







VO t^ 


fv 


ro 




00 VO 


in 


rooo 


01 




VO 


■<*• 









VO 10 10 (^ 


rr 




<N VO 


t>N 


(N 00 VO 









ro 


tn <M VO 00 


t>» t^vo 


00 




Ti- 00 00 00 


P 


CO 


0. 


<N 


M 


H t^ t^ 


in M 00 VO 


ro N 


n 


0^ t^vo 


in 


in 


Ti- ro H H 





H 




t^io^->4-roroN M 


(N 


w 


w 


M 


K 


^ 


M 


M 


H 


i-l H M 


M 








CO 


N 


VO 


rg 




ro 




t^ 


„ 






rovo 











CO 


(N 


VO 


crs 




ro in 




i-i 


M 




ro ■<*- 




^ 


VO 


ro 


in N 00 


VO VO 




m 


(N 


H 


M 


(N 


-^ 


00 00 




M 


t^ M 


H Tj-oo Tj- 00 


in 


ro 


N 





O^00 


r^vo 


in T^ <N H 


^ 


M 




t^vo 


10 Tj- 


ro ro fo (N 


04 


N 


(N 


w 


H 


^ 


H 


H 


M 


H M M 


H 











VO 




'-J- 


H 




in 


H 


rooo 




« 


in 




2 




■^ 10 VO 




» 


t>N 




M 


H 


rovo 




»n Tj-oo 


a 


»o 


H 


CM VO 


in 


M 


tn 




VO 


-* ro ro in 


I^nVO 


t^ 


w 


NVO 


XT, t^ 


M VO ro 


t^ in ro w 





o\oo 


t^vo 


in ro N 


M 


IH 




00 VO 


ir> -^ Ti- ro ro ro N 


(N 


w 


N 


0) 


•^ 


H 


M 


H 


tH H M 


H 





S 


H VO ro 

t^ VO 

•^ in VO w ro 


in 
00 
w 00 


N ro M H 

in ro N 00 

in ro ro T^vo m 


H 




ro 


M 


00 N N ■^OVThHOOVO 
C^VO m '*• CO 0- CO N <N 


^ N 
N W M 


Coo t^vo in Tt- 

M M H M W-'M 


ro (N ii 


M 





ro " in 

ro T^ 
N rovo m 


VO 

00 -"i- 


•<*-vo '^ N 
vc VO 00 r^ 
t^vo VO 00 W 


ro 
ro 


% 


•H 


rj- r>.VO 00 (N t^ ro 00 

oovo lnT^T^ro^oro(N 


in rh N 
(N (N (N 


M osoo r-.vo in 

N M W M (H M 


■<*- N CM 


M 



M ■<*- VO 



ro VO t-^ 
VO Tj- in 
ro 00 00 



VO 
VO 
00 VO 10 



M ro 
0^ ro 
O fO 



VO (N VO invo 

VO in M (N in -"i-vo 



in H VO VO t^ 00 

t^ "^VO <vj N in N 

ro Gnvo in in fx m o^ 



t>^00 in inoo ro ON in P) O t^vo tI- n m o o^ t^vo m ro 
Ov two mTj-TfcorocorowcjwwNWMMMMM 



vo M t^ 

VO 00 O 

invo M ro 



in ro m 
in O ro o 
N t^ ro M 



u^O»/^0>^'0»'lO"NO>00»^ 
C4 ro fO ■^ -«t m vnvo VO t-s r^oo 00 



0000 
M cs ro Tf i 



•sa33HA\ TiH^rasrviM 



248 



I 



PINION 20. 



J8 



N M N m 10 O VO mvo 10 VO NO t^ 10 

^ _-^iOM t^rOH t^>o t^ r^ IT) ro M o 00 

lt/> VOMt^M WOOVO lOvo 00 H IT) ir;vo ^J^ ro C>i 

*ft|»»»» •• 

1 ■'l-COCONNNMMMMHM 



iH o O Onoo t^ t^vo 2 



fOVO 10 N 

»n ro LO CN w 

N 00 00 00 tH CM 0\ 



VO VO 00 (N N -<1- w 
•^ O 0^ On O N vO 



00 00 -^ 
tn O rovo 
-^ 10 t>. O '^ 



(>» two -(I- ro m N 



M O Onoo 00 t^ 



10 
On 


VO m 10 fooo 


t^ 

(N 


00 -^^ VO 
fOOO 10 H VO 
U-) CO N CM r^VO 


ro 0\ N 

VO VO ■<^ 
Tj- m ID t^ H 




CM 


t>. tnoo CN 00 to N 

10 -^ rO CO M M CM 


s 


ON h^vo 10 -^ ro N 


(MHO <7\00 00 













VO ■^^ 10 ■* Th m 
ir> VO 00 r^ ■<*• 1000 

t^T*-M MOO -^txTl-lo 



M VO 1^00 N 

"■J-VO ro CM (N 
VO ■* Tl- ID t^ 



tN, H M 

in cs Oi P) 
ro cs (N loco 



fO 10 H VO w 

CO IT) 10 00 VO VO 

ID P) ro W IDVO H H rj- 



f«-, ID t>. t^ 
t^vo VO t^ 



H CD O 

OnOO ro 

CO O O N 10 



VO CD ThcXD CD OnvO -^ c^ O OS t^vo iDM--<4-rocq m O 0\ 

VOlDTfCDrOCM(NC4CM01MHHIHI-lMMMMM 



■<^ IDvO 00 N t^ 

•I CM VO O ID CJ ID 

ID r^vo VO ID On t^ O ro 



W rh m -^ ID H CO 

M VO CD ID ID r^vo t^ 
00 t^OO W OiOO 0\ H 





VO 00 




■<1- 




m ro Thvo 


W 


CJ 00 




VO 


„ 


t>. 




?> 


VO 


N 




Tt- 




m w 


M VO 


ID --J- 


(M 


t^ 




VO VO 


ID 




H 


VO 


"^ 


ID 


■<!^ 




m On c^vo 


t>. 


CM 


ID 




M 


■«J-00 


w 


ID ThVO 


M 


r^ 


Tf <N 


00 VO 


ID ><*• (D C^ 


CM 


M M 





C7N00 


t~* 


M 




ID "<*■ <r> CD <M 


<M <M 


W 


M H 


H H 


H M 


M 


M H 


M 











R 


ID VO 
00 VO 
N VO 


00 H <M i^ CO H <y\ 

HI VO -^ H CO CO 

00 •<t- M M COVO ON 


"I 
CO r>. 

W »D 


s 


IH 


00 -^ VO 
VO -^ Tj- CO CD P) 


•>!^ M 00 tvvo ID -<*• CO pj (M 

CMMMHMMMMMMHMH 


CTvOO 









ro pj 00 

CD r^ 00 
CO H 1DCX3 


VO VO H CO -* rhOO 00 CO 

co'O f^ CO ID On -^oo h CO 
VO VO ID CO CM P> •<i-'0 00 00 


^ 


% 




ID P) ro r>. cv) 00 

VO ID ■<*• CD CO W 


VO CO M 00 t^VO ID ^ CO CO H 


ON 


H 




WPIPJPIMM MM 







"^ coco CO O '^^ t^vo On 
IDCOCO CO t-^iDCO pjvovo 
■"^COlD VOlD-<j-lDt>» t>.VO t>. 



Ow^OV)OmOv>Ow^Oino»nOviO O O 
N CJ CO ro -^ T^ ID iDVO VO C>. t^OO OOONONQMPJCOrJ- 



C/3 



133HAV 'laHQNVIM 



249 

PINION 20. 



00 


(N Vp 


10 M H 
■<:*■ 10 VO LOVO t^ 




CO t^ N VO 10 

ro ro t^ -^00 
ro t^ w w 1000 (N 


M 


w rt- Omd N 
>o Tj- ro N <M (N 


00 f^ to Th (D (N 


N 


MOO a^oo t^ t^ 












in 
00 


»0 ro t^ (N IT) 
N W 00 lOVO IT. 


H VO t^ m CI 

0^ M 00 ro H 

H -^ t-> t>.00 




t^ H 1000 M 
r^ ro m -"i- 0\ 
<N VO (N 1000 


J 


10 -^ ro (D <N M 


(N 00 t^ IT) Th ro 


ro 


(N M M O^00 t^ 








H H H M 




«0 


VO Tf VO ro tv, VO m 

VO lO'^ m en vot^ 

invo VO t^ ^00 VO 00 ro 00 c» 




OJ VO 00 VO ro 

(N CM M M m 
M IT) OVOO G^ H 10 




Ov t^ Ov •<*- OvvO 
ID -"l- 00 ro a (N 


ro M o\00 t-N 10 Tt- 


-h 


ro w M 6 c>. OVOO 








M M H M 





00 t^ ro M „ IT) tJ- 

(N Lo ro 00 in w H 

m -"J-oo ro w C4 VO M 



VO >-i in t^ t^ 

VO (N in On N O 
M ij- t-^ mvo 00 w 



a 


CO in 
in CM ^s. 
t^ CM in -^ ro 


m ro ■<*■ t^oo 

-^ m in M 00 m 

w in (N M CM -^vo 


CM mvo t^ 

in t^ N t-^ 

m 10 t>. H m M 


m 

ON 


w "^00 Tj- M 0, t^ in 

■"il-rOtNCMCMMWH 


Tf ro N w 

jH H H H 





0^ O\oo tr^ t^vo vo 


& 


tN. ID 


ro 
VO 
ro 


VO t^ 
00 00 


00 

moo 
M m 


00 H rooo 
VO 00 CM CM 
T(- M m ov Tt- 


8 


invo in (N CO VO 
■"^-rorocMCMNHH 


>n ro (N CM 


H 


O^ C>00 t^vo VO 

M 




& 


00 in 
invo IN t^ 


CO 


00 M 

ro T(- 

in CM Hi p) 


m tr>. 

rovo 


H c^^ M 
CM m w t>, 

■<J- On (N VO 


© 

M 


<y\ o\ rooo -+ CM 

■<<- ro ro CM CM CM 


000 VO >n 'd- ro 


CM H 
11 H 


M On OVOO t^ C^ 

H M 


a 


m 
« 00 


VO 

ro 

VO VO 


moo in 

H N 

VO rf Thm t-> 


ro CO t>. rh 

VO M i-i 

rooo 00 ro t>. 


s 


■«!l- rovo ^^ "* 
m rf CO ro w cm 


w cDvoo VO m -t- 


ro « 


CM M cy.00 tx 






*^ 










8- 


CO 

CM in 
inoo s- (N 


CM 
'^ CM 


■<*• in -<4- 

H (N VO 

in t^vo VO t^ 


m VO t>. 

M ro m m 
ro t>^vo t^ ro 


% 


00 VO Oi ro o^vo 
m "i- ro CO CM m 


ro M 

CM N 


Cj\oo VO m 

M M »-: M 


-* ro 


ro CM H as a^oo 

M H H W 




a 


-* m 


OS 
M OS 


00 
ro 00 


ro 
m (N 
t^oo 


M^O ■<*- mvo 




mo CM VO - 00 
VO m ■<4- ro m CM 


in CM 

CM CN 


H« OVOO VO 


m T^ 


'^ ro CM M C^ C3\ 




*^ 








8v 


m in (>• 


in 
in 


0\ in 

VO 00 

in t^ N 


m CM 
t^oo 

00 00 


CM Th CM 

M t^ moo Tf 

CM m CM CM rovo 




t> Ti- inoo ro t^ "* 
VO lOTi-rororocM cm 


CM c^oo VO lnlnT^ro^^ h 0\ 




CM (M H H 




------ 










































••"•***' * * ..••• • 






Oinomoinom 
CM CM coroTt-.i-inin 


Q m in in 
VO VO t^ t^oo 00 


§^^82gg,|' 





03 



'SiaaHAv aaHQNVK 



PINION 20. 



<7J 

5 

h 



vo t>> t*» 10 m t^oo vo HOOH wvo^OT^> 

vom tv "^foONVo Hoocj t^vo U-) M j 

vo 00 IS ^ 10 CO CO TfVO -^00 rf N vo H t^ C/ 

I vd ci 6 t^^ -^ 'O N M d 6 ONOO 00 00 t' ^d vd IT) I M 



CO On ID 
rovo 00 

•H O On 0\00 00 t>.vO vo 



00 rovo 
00 vo vo fO 
00 ■^ rcvo N 



VO Ti- On 
c^ Ti- r^ 
O 



CO ro H 
M rovO 



cS 


•^ 


00 
CM 


cn Th On Tj- 
ro m vo H 
CO w -<*■ c- t^oo 


-^vo in t^ -^ t^ 

ONVO CM 00 »0 

CM vo M vo t^ rooo 




CM 


00 00 <N 
rf CO Cf 




H On r^vo -^ ro N N 


HI ONOO CO c^vo 








M M H 





00 


VO 'S 


^ 
t^ 


H M ro t^vo 

M 00 fO tOMD 

H 00 On fo 00 00 


in ir, « irjvo 00 
en ir> ^ CJnvo n 
0) 10 On ■<*- -"i-vO -^ 





N H "^ OnVO 

10 <^ m (N N 


MOOO t^VO -"i-rOfON <H ONOO 00 C^ 













00 


vo Tht-sCMOO -^CM 000 t->VO 
lO'<S-fO<T)CSCM (N CM H Mw 


-^ 


-* ro CM M 


H 


ONOO 00 


l-l 


a 


in VO c» M CM 
00 vo M VO T^ 

(N vo CO -* M 




H CO m 

H fOVO 




C3n m 
rn f^ 
ON W 10 



10 


000 rJ-QVO -^ M 000 t^VO 
VO'^'*-fOrOCMC^(NC^i-lHl-( 


IT) Tt- m CM 

M H M H 


(N 


ONOO 





00 


t^ 10 <3N ONOO CJ fO Tj- LO -rj- T^ 

m 10 CM lovo CM vo ID U-) Ln r^oo vo 
CM vo toco M fOC3N^^«tr^C7^CMln IDQVOO rooo -^ 


8n 


000iDi-t<3Nt^tDro(>jH00O\ ONOO 00 t^ vo m ID 

rOCOCMWHMMMHHHH 


10 

c» 


10 VOHt-^Tj-OMOO rovo voro N id(NC?nmoo 
t^ H r^OO -^ IDOO ID eg rOVO 0, t^ C-^ Tf- (N « vo 
CO CO 0^.0 H ONHVO -^-^iDt^O IDONIDO rOO,(N t^ 


ID 




CM vo fD t^VO Tj- CO CM M ONOO CO C30 t^vO VO ID 
^fOCNCMMHWWMHHMM 



ID 

cx> 


fO ID ■<i-vO VO 0) ro ID Tf- M t~^ '^00 H 

rooo >D iDvo t^-^rocM ^t1- CMOoror^ 

ID rOC^CJOO ri- M 1-^ CDVO 'i" ON ID t-^ '-O 


8 


N 'i-oo TfMoo t^iDThcoM M ON.oo 00 t^ r>.vo vo 

M-COWCMCMWI-IHWMHHHH 




10 

00 


VO-<*-lDt^ mTft^VOf->OOM MCMOO 
ID vow-f^r^ OOOOiDVOOO CO-^iD, ONO\t-«, 

t^TTMt^rot^t-, m m en -^vo o-;0C ro id c>^ m vo 




M 


vo t-MVO COOOO t^lD^m(>) w H ON ONOO t^ C*»vo 
TtrOrOCNNWMHHHMHMHM 




0lD0lD0»D0lDC)lD0lD0»O0lD0 C 00 
CM M CO ro -"^ -"^ ID IDVO vo t> CxOO 00ONO^0HCM^OT^ 





siaaHAV i.'^^^cK^r 



FINION 20. 







in 


in 


N 


•"^ N 




t^ H N VO in CM 






in 


00 


t-^ 


t^ 


in CO 


T(- 




ro ^ in in ro (N On 






tx 


in CN 00 


in M 


w rovo 




■^OMnn t^MVO M 


a 


m t^ 


N O\>o in 


CO w 


M 


o> 0\<x ^ tx t^'O VO m in 1 




m CM 


M M 


w H 










1 






m 


«o 


w m 


in 


in M 00 




(N VO m tx r~s M 






<N 


in in 


« ro 


in in 


c>.vo 


r^ 




VO 00 H cs r^ rooo 




ir, 


-o in 


c^ roco 00 


(N 0,00 ON 




in 


OiroOMOM rhOi-^ 


m 
0. 


in 00 


m 


t^ in 


-^ (N 


- 


n 


000 00 fx t^ t^vb m in ! 




ro M 


0) (N 


W H 




M M 


M 




1 








00 


vo 


VO 


t^ 


Tf 




in ro ro '^ 00 00 








N 


invo 


ro 


ro 






r^ 0) ro On m mvo 





m 


in 


'^ 


t-svo 


VO 


m in 


tx 




rooc rooo moo ci t~>. 





rx 
















1 


M 




tx 


m H 


00 VD 


10 ro 


M M 








ONCO 00 t>> t>.vo vO m 






ro en <N C4 


M M 




H M 


M 




1 








^ 


in ro 




(N 


m 




(N 00 VO Tj- mvo 






in 


!>• 


(N ro 




in o\oo 




H mvo 00 in (^ •'ij- 





5.0 


w 


in mvo n"; 


m 


t^VO 


tx 




ro c^ H VO N moo ro 


H 


Cx 


















fH 




H mt^mooovo in 


ro (N 


H 


M 


On 0.00 00 t^vo VO 






■* CO (N N 


N M 


M M 


M M 


'"' 


"^ 


•^ 








^ 




CN 


vn 


r^ 




00 M M ro 








M 




VO 




m 




moo t^ 00 (N 





ir, 




t^ 


ir. 


CO 


00 00 




<N m Tj- M m ON 


(N 


ts, 






















invo 


m 


(N 00 VO 


m ro N 


(N 


H Oi ONOO t^VO 






T^ m 


m (N 


(N (N 


l-l M 


M HI 


M 




H H M 








VD 


ir.O 


'>>. 




00 




t-^ m CO ro "^ m 






-^ 


in 


t^vO 


N 


IT) 


r>j 




00 t^ rovo mvo (N 





in 


t-^ 


moo 


rovo 


in f^ N 


C7n 




H ^00 (N t^oo w m 


ro 


r^ 


















M 




00 Cy» N t^ 


Tj- M 


Oi t^vo in 


ro 


n- 


N M Onoo 00 tx 






■"^ fO 


m N 


(N 0) 


H M 


H H 


•^ 


•^ 







m N VO N m vo 
N mvo m ■<!^ m t>. 
M rovo o m m t>N o 



ro rt- 

ro H 

■* ro tx 



00 VO (N tx ro H 

M VO On m ro T^ 

00 Noovovooo M moi 



On rovo 

O "^ ■* 

vo On moo 



Onvo m ro W 



O O ONOO 00 00 t^vo VO m 



mo mo mo mO m^ 
m mvo VO tx t^oo 00 On On I 



m 
tx 


CN m 
m T)- (N 

M m H H 


T^ t^ H CN m 

m m t^ VO ro 

m -<*• rx ro w 


N t>v in ro 

■^ m N t-^ m 

moo N CM rovo 


a 


VO m tx (N 00 m 
m Tf CO ro <N <N 


(N 00 t^vo m Tf ro 


Cl 


M M ONOO 








M M M 




a 


VO 00 M 
N VO -"l- •■< 


ro ro M Tt-vo 

VO rovo H VO 

VO ro ro -"I- i^ m 


m 
in 
m 


I^ MVO 

m 00 VO ro 

H 00 H VO (N 


m 

00 


Tt- t^ Cv) On tx m 

CO N N H M M 


ro CM H On Onoo 00 


c^ 


t^vo VO m m 



00 


M 

00 m 


w VO m 

C3N t^OO l^ 
•^ 00 <N VO -<i- 




C3N m 00 
t^ -^ ro 
m CN m On 


8n 


Vl3 00 -^ 00 VO 
m CJ (N (N M M 


Tt- ro CM H o\ a\oo 00 


t^ t^vo VO m 



•siaaHAV "la^iQNviM 



PINION 20. 





m N 


to 10 o^ 
t^ VO -"i- lovo 




in H CO t>. VO 

r-> M N in Tj- 
■^00 M- VO CO t^ M 00 


8. 


w in H 00 

CO N W H 


10 Ti- N M 0^ O^oo 


t^ t^ t>.vo VO in in -"i- 


^ 


1 

to vo 

W VO H 


lOVO W CO t^ 

N t^ o^oo CO 

VO f^ CO M 


VO 
in 00 


N COOO m H 00 
M M 00 m -^ ■'J- M 
cooo CO VO m M 


to 

ON 


f^-VO W 0^^0 ■'t CO (N H 

mOCMMHHHMMH 


OnOO 00 t>- C^ t^vo VO to 10 


^ 


CO 

ro 

CO 


to t^vo 0^ 
10 « vo VO 

to 10 t^vo r^ 




in t^oo CO CO ■<*■ 
w in CO t^vo VO cooo 

CO tr^ W t-» CO cooo CO 


8 

H 


moo CO 

CO N CN M 


t^ m Tl- N M 





onoo 00 t>. t^ t^vo m to 


g. 


1000 VO 


H CO -^ 
IT) H CO H 
W M -* 00 t^ 




VO moo in 01 VO t^ 
VO (N in m in m m 
(N vo m H t>. -<^oo 




H 
M 


00 0,m N 
CO CO M M 


ON t^ 10 '<*• CJ M 

H H M H h-l H 


1^ 





On onoo 00 t^ E^vo in 


^ 


VO 


VO « CO 
VO t^ CJ 
VO 00 W ON 




N 


c^ CO N vo M 

00 CO -<*• CO VO 
l/NOO cooo Tl-VO Tj- 


H 


CJ coco -^ 
-^ CO w w 


H 00 VO 10 Tj- (N 

W M M M M 1-1 


M 


M 


On Onoo 00 t^ t^vo 


R. 


lO •^*- CO 


N lOVO 
10 « Tj-vo 
t^ W N 10 w 




CO inoo H 00 w CO 
CO t^ m H t^ t^oo 
Hcotv.MinHc^in 


^ 


invo VO 

'"i- CO CO N 


N OOOVO lO-«:hCOM 
CgCNHMMMMM 


H On Onoo t^ t^ 




a 


VO 
N VO 


t^ vo cr.yC 

t>. M CO c-^ 

10 t^-VO 00 CO 




1 


M 00 N 00 VO 00 
rnvo 00 11 VO CO 
M moo cooo On H m 


% 


o> o^ N 00 

"<*• CO CO (N 


■«*■ H On r^vo 10 Th 


CO 


01 w Onoo 00 c^ 






^ 










g. 


to 


CO CO 

10 CO ON 10 

01 CO 10 M 






m « VO (N m VO 
M mvo m T^ in c^ 
M rovo in m c-~ 




« « 10 
m -^ CO CO 


VO CO M ON t^VO 


in 


■<l- 


CO 01 H H ONOO 00 














to 




CO ON t^ 

CO CO 
CO On 01 


in 




00 VO m Th 00 
m NO CO -<!*■ VO 


eg 


Tj-O I^IOCOC^ CJnOO 00 
CONMHMHMMM 


r-. t^vo VO VO m m ^ 


K 


to ^ t-«.VD 10 t^ 
t^, in H COVO LO On N 
00 to 01 M 0^ H t^ lOMD 00 




H 


00 CO in in CI CO 

VO 00 M r^ On M 

inONLOO t^COt>.COON 


m 
00 


M to H 00 

CO N W M 


10 Ti- N H On OnOO 


c^ c^ t^vo VO m m ■<*• 




(/3 



Omot^otootoQtootootoOioo 000 
c» « CO CO -"J- ■<*• m mvo VO ^^ t^oo 00 o^ On o m n co 



'saaaHAY ^la^aNVH 



PINION 20. 



CO in 



t^ W N t^ 00 10 

m H 00 IT) 10 H t^ 
moo moo 10 M 00 rooo to 



C^i M 0^\0 -<*- fO H O O O^00 !>• t^M3 vO vo lO u-j tj- -.^ 



m ONt^N t^H M rooo '^ H 
t^ oo-^ro(NincNO\ oroMVOvo 

00 t^ 10*0 -<i- t^ ro N N IDOO N t^ M 00 



li-; ro 10 

t^ 1-1 Ti- 

H vo M 



O C^OO 00 t> t-^vo vo vo 10 10 -^J- 





vo H •* 00 CO 

vo t~^ 10 -^ H ro 
lO vo 10 M ^ 00 00 




lOVO 10 t^ N (N OnVO 
OOVOM-^tN-^ O" 
NVO MVO <N00 l/~. 0\TJ- 


8 


Nvo Moovo -"^mH 





o\oo 00 t^ t^vo VO m 10 lo 




10 

vo 


moo 1000 vo 
lo m N c>>oo w 
c^sO 00 -^00 00 m a. 




Tj- m t^ H T^vo 00 
HmmHTt-cNvo 10 

M lOOV^ONlOH 100.10 


2 


u^oo m 

m M (N (N 


t>^ 10 '^ m H 


H 
H 


000 00 t>. t^ c^vo 10 to 

M 




10 

VO 


10 


m M 

m 00 

10 mvo H 




(M vo vo 10 
■<*• 10 t^vo M 0\ 
H M-t^i-iVO CNOO to 


H 


Q\ H vo N 

m ro w N 


o\ t>. 10 -^ m N 


M On Onoo 00 C^ t-.vo vo 

M M 


v^ 


NOO H H 


10 t>^ mm 

N c^ vo 00 
M t^ ov m 




HVO(NH00Th HM 
txVO vo -:J-00 O\lO00 ^ 

(N 10 On moo T^vo »o 




m 


(M moo -"^ 
-^ m <N 01 


MOOVO lOT^m^JH o^ o^oo 00 r^ t>-vo 


to 

vo 


m 
to "^ m 


N lOVO 
10 (N "^vo 
t^ N N 10 H 




m looo H 00 N m 
m t^ 10 M t>, t^oo 

Hmt^HlOHNlO 


^ 

K 


xovo vo 
■<1- m m <N 


(N 00 vo »0 


•«*• m N HO a. ONoo r^ t^ 




CM N M H M 




" " " " 




^ 


t>. lOVO t^ 

10 10 r^vo (N 10 
t>. 1000 mvo 10 c^ (N 




00 rv 10 m m m u-) 

N 00 t^ mvo lOVO (N 
ON M TfOO N f^OO M 10 



10 


00 On M t^ 
"■i- m m N 


Tt w 0\ t^VO 


10 


m m, (N H onoo 00 t^ 






N W M M M 









lOVO 10 VO 
w vo Th 10 c^ 

10 MVOlOlOt^QlO 



« vo mvo N if 00 
vo c-^mcN lot^^fo 
lOHoo ION r-^mo 



O Onoo 00 t^ t^vo vo 10 vo 10 ^ -^ '^ 



I «^ 



vo 

vo 

-^vo 



H m 10 
00 m M 
M mvo 



00 0) '^ O vo t~-> 
00 W ON ONVO o 
10 ?j 00 vo o vo m 



O Onoo 00 t^ r^vo vo 10 10 10 ■* ■<i- 



m 10 M 00 vo 

10 m t^ N HH M 

t^OO 00 00 <N ONOO ON 



m r-^ 

m m 

>0 ON -<*• 



M m Onoo vo 
M vo 10 O m r^ 
vo (N On ■<*- On 10 



ONmONt^TfmH On onoo t> t^ c^vo vo 10 10 'i- ■<*- 



OiooioOtoo*oQioovoO*ooioOOOO 
w w m ro "<*• -^ 10 »ovo vo t>s t^oo 00 On ON O M N m 



•S133HAV aHHQNVH 



254 
PINION 20. 



00 vo 10 Tj- 

LOVO H IT) 

10 O 'O 00 -"i- 



O C7^00 CX5 C- C--^ VO ^O lO XT) tJ- 



t>. vo rooo -*• m t^ vo 

rj- cj invo N w '^OO 04 t>. ro Oi^ 10 O 

m^ Noovo -+roc* h o Oicx) 00 t^ t-N.vo vo vo 10 10 

fOOJNMMMIHHHH 

H Mvom mooiooo 

r^ On 0.00 t^ r^ -r ro 

CO U-) ^O :)(N>0 T^ u-)(NU-) IT) 

vooo Thooovo ^m(N H o 0\ o\oo 00 r^ i^^vo vo 10 

rOWWPJMMHHMHW 

T^^OM (N vovotoON 

00 00 00 T^ Lo r^vo « o\ 

N CN 10 mvo >H MTf-I-^MVOCNOOOU^ 

OnmvO CS- OC->i-OTl-roCN r-i O On C^OO OO O^ t>«vO vo 

rOC^eNOlMI-IMI-IMIHHM 

vO(Nm CNo-;csvOH 

vo t^CM ooro^rovo 

vo vo 00 (N Ov N 1000 rooo ■<tvo -^ 

(M ro-X) -<J-i-iCOvO >nf(N N M o ON Onoo 00 t-^ t^O 

rrrOCJ(N(N-(P-tMMMI-l(HlH 

T^ rovot^ oofOMcn 

M vo ■"d-i'^iOOO t^OO W 

t^io rooooo win -<*• wioON 

invo QiJ^CSOOOVCmrO'^lNMOOON O^.OO O-'O 

^rOrONWCNMMMMHMMMH 

vo 10 M ojro vor^omoN vow 

in vo t^ HI r^oo vo 00 m moo m moo 

t^NH fOHHWU-) mOvOrOOt^iDMD^u-) 

CN 00 U-) m M o Onoo t^ f^vo vo iriir:m-^^-^cncn 

M t-l M H M M 

m oot--.ro com rh ro r^vo m i/i m oj 

t^ m (N 00 ro rnvo o vo on m m ro t^ rovo m 
ro ID M On M 00 t^oo w toONioo r^'^Hoo -^ O t~~ 

Tf onvo ro n O onoo 00 tr-^vo vovo Lou-jio-^-^^ro 

CN M M M M M 

0-, c^ m Ti-vo oom t^t^ro t^m 

ro in in invo n ro m c^ r^ oj ro 

09 rooo in r^ Tfvo Ti-CNinw t> ^w t^ro 

vo o r^ -i- m H o onoo 00 ^^vo vovd in m ir, ^ -<t- ^ 

M W HI W H M H 

■* vo in pj t^ -"^oo wvovo commcMTh 

N HOOMt^in-^O OnQO (DmcnwOU^ 

vo M -4- t^oo w o o o inoo mONinMoo movo w 
t^woo inrnw M o ONOO c^t^vovoo mmm-^-i- 

NWMHMIHHIH 

0»J^Oi'^Oi'^OinOioO»nOioOioOOOO 
w w ro ro '^ -^ >o mvo vo t^ t^c» 00 o^ On O m n co 






•s^a3HAv qaHaNviM 



>8 



255 

PINION 20. 



10 


^>vo woo Tj-rot> vo 

rj- 00 »OVO N M Tf C30 W t^ ro ON^ lO 





COVO CNOOVO "^fON M 
COWNHMMHHMM 


ovoo 00 t^ t^vo vo vo »o in 


^ 


fooo IOCX3 vo 
t^vo 00 -"t-oo 00 ro 0\ 


'i^- ro t^ M rt-^ 00 

HrorowTi-cMin in 
« inovrt-osiOH inovm 




looo mo t^inTt-rOM m 


O^oo 00 !>. t^ t^vo m in 


K 


vo M fO>0 
vo IT) M ro "^ 

1000 vo « M T^ 00 00 


vo inoo m (N vo ro 
vo N in m m h (n 
(MVO0"~>Ht>N •<i-0^ 





00 IDN 0>t>«»O-<*-N HI 
COCOWCJMMMWMM 


H Ov Ovoo 00 t^ C^vo u> 

H M 




»0 t^ CM ro in ovoo m mvo 00 to t^ Tt- 
N in mvo ro in t-^vo r>. ro c^ h vo w moo ro 


M 


M cot^roOoovO inroN 


w M Oi OVOO 00 t^vo VO 

W M H 



vS 


N vo H M inoo ro N in 
^ invo c\ t^ t^oo ro m -<*- m 
mvo H t^vo ooQio mwoomcoHOvmN 

OMn ro H o^oo «>. t^O v© ^o^o•<4••*"««•T^fOcococo 

M M H Ht 


vS* 


-8 


rovo w mvOmoo 

ro ro vo in -^vo c^ >-> m 

CO ^ .*?^'t'^ -^ vo « ONVO <«1- « 00 in M 

HI vd ""4- W Ovod C^ t^vO vo mu>Tj-Thr5-Tj-cOCOCO 

W W tH !H M 


a 



5 


in 


i^ H rooo m -^ vo H w 
mm 00 WW wONroov mvo 
ooM nmoN-^ vow t^mot^"* 


m 


w 00 in (N M O^oo t^vo vovo miow»Tj-'^Tfroco 

<M M M M M M 


-8 


N 


■* vo ^N -^l- t^ tx ro N ro w 
MVO (Noom n-romvo o\ 
t>. vo vo t^ rooo Th vo ro 00 CO vo 


<S 


OJ M t-1 


CO w Ovoo 00 t^vo vovo mmm-*-*-<trr 

M W M 


«8 


m Tj- 


H rowvommvooovo ro 
t^ m ro t^ -"i-oo t> vo vo ro m w 
m t^ CO w <N moo wooro voroMVOwo> 


m 

00 


mo t^ t}- (N H o^oo t^ t^vo vovo ininin-<4-->4-ro 

« M H H H M M 




, 


00 OOrO-<*- tM'<*-ONVO 





- -- O -- . , 

vo Tj-in 0000 ror^wc>.ro vo-^ovmHO 

I ov ; 

^^H00mro^)0O^ o^oo >• t^vo vo vo m m •<*• -^ " 

W W M M M H H 



moo 


m vo ro ov 0) moo ro jh T^ 
00 mvo vo vo Tj- (N m ro 00 moo 
wwvoT^romt^MVOHt^ro t^Mt^co 


^ 


^S 


o>vo rj- w w Ovoo 00 t>« txvo vo vo m m '^^ -^ 


























gs'^i^e^s.Mv^a^^c^as^s 2 ii 





•siaaH^A i-^aaMviY 



256 

PINION 20. 



]^ 


00 CO 

« 10 CO 

10 « -vj- w rovo 


to ■^ to N vO CO t^ 
t^w NOOVOt^ toco 

toot^-^woovo-^co t<»to 


3 


CO M o\oo t^vd v6 sn»0'<*-'«i--^rococorocoN ci 

M M M 




0. H M CO t:^ 10 

00 CO a. W Ov On H 


00 t>sVO 00 to CJ CO to On 
10 vo vo t~^vo t^ to C^ to 

tOOVtOM C^Tt-N OVt^tOW ONt>« 


^' 


t^ •* H 00 t> t^vo >o»o»o-<4-'<i-'*-cororocooi N 




CO »n»o 


VOCO CONOVt^N OOH 
MW fOlHNt>ilOlO QVO 

•^cmomoo tow 000 tow o\ 


g. 


OMO N w OnOO C^ t^VO »OiOlO^'<i-"<i-'>4-COfOCOC« 


ss 


to 10 « vo 

CJ tOOO H VO lO 
vo to t^ t^ CO H « 


lOVO 0) vovorOMiO t^fO 
t^ -^ ON in c^oo -<i- N to CO t^ 

tOOO COOO lOMCO lOcOH O-^M 


?: 


VO CO H ONOO 
CJ W M M H 


t^vo vo lOioto-^-^-^-^cococo 


:a 


vo t>s t>, 

vo vo to t^OO 


CO On lovo vo 00 m vo '^ 
covo 00 vo c^oo CO vo 00 

COt^WOOlOMOOVO-* <OCO 



00 


N t^ ^ M H OsOO 00 t^vo vo lOlOtO'1-Tt--*-<l-COCO 
N M M H H 




to ro t«» t^oo Hojooforo Tj-Htn lovo 
t>. 00 1000 ooto o^o^^^»^OT^ ChcNt^ioChO 

CO C^ vo fOVO COCOtOt^MVO NOO ton 0\V0 N 00 to 


to 

00 


COOO to CO M ONCO C^ C>»V0 vo lOlOlO'^-^'4-COCO 

N M W M M M 


10 
10 


N to 
to Tj- C^ 

^N0O to M CO On 


to H 10 fO to to t^ 
lOiHC^ ooc) Mtn NO 

NVO QVO MOO tON OnIOwOO 


8n 


rf onvo tJ- cm h on Onoo t>. t^vo vo toto»o-<4-Tt-Ti-ro 

W l-l M 1-1 H M 


10 


to vo 00 0) M 00 00 -^-vo M tv. 10 to ■<*- o^ 

N M (N vo M to COVO VOrOT^O NIOVOM 
■tl OV-^OVQVO Tj-tOt>.0 "^ONIOMOO tOM t^COO 


^ 


vo t^ -^ ro H 

CJ W H M M M M 


ONOO 00 t^VO VOVO tOiOto-*''!-''*- 


I^ 


CO M 10 N 

in CO c^ c^ 01 


VOHt-^COlOlOMON coo 
VOVOlOCOt^t>.H00 ooco 
M Ti-00 COOO Tj- w c^ to 10 w 


§ 


t^ oj 00 to CO e4 H 

C* W ft It M M M 


ONOO t^ t^VO vo vo to to to ><*■ "<«- 


S^ 


vo t/> Y> Th 
10 vo 00 N Tj- 

CI « M W M Tj- M 


covo NVONC^NOO MOO 
00 C^ "^VO vo H (N vo to Tt-OO 

covo lOM t^roo toovo 




M 


"^ t^ to CO N 
CO W « H W IH M 


H ONOO 00 t^ t^vo vo vo to to ■* 

M M 



Ow>0»oO«OOiOOtOO>'>OtoOtoOOOO 
e» « ro CO "^ •«<■ to lOvo vo t^ t^oo 00 On O^ O •-• N CO 

•H M M M 

•- ^ ^ 



5 

H 



257 

PINION 20, 



8, 


e«» »r> t^ CO ro moo wc^ro vo-*HO\t^-*woo 




»-• H H M 


a 


fO CN 00 i>.vO lOHfO tOTfM rorot>* 


eg 


CO CO w 00 00 t>.>o vo iou-)io^Ti-rh-<*-cnfOco 

N M H H H 




a 


vo CM vo Th t^ rooo MoocN NfO roHON 
JO vo-*(N**- M0orot>.-OM (N t^invo --tvo 

©) Mi-iVO-^lOt>.0"^OVOCO t^'<^(N00lO(N 


CO 


M t^ Tt- (N 0"00 t^ t^vo vo iomir>-^rt--<^romm 

« M M H W 





H rooo u-) Tj- vo H M 

CC (N (N (N On fO On u-jVO 

hioON'^ vOC^ C^iDQt^Tt- 



N 00 »o N H o Onoo t^vo VO VO in m m 



a 



roMirjiO vovovou-jroc^oot^ 
ro t>> t>» ID ro M t~«.oo ro rooo c^ 
00 1000 m lovo ON ro c^ ro ON ID c^ 



00 00 00 
in H inoo 
t>. ro ONvo I in 







vo 


in 




IH 




^ 


ro 


N 


0) vo 




04 in 


ro 


rnvo vo 








vo 00 








ON ro On 


Tfvo 


inoo invo 


Tl-^ Tj- 




2, 




VO 


M 


in 


H 







rovo 


M vo 


(N 00 in 


01 


in 


M 00 


8 


in 


vo 


^ 


rj 


M 





On 00 


t>. t-^vo VO 


m in in m 


T^ 


^ ro 




(N 


(N H 


H 




M 




























fO -<*• 




N 






vo 


i_i 


r^ ro 


in 


LO H 


<3n 




ro 








ro 


M 


in 


0) 






vo vo 


10 ro 


r^ 


C^ M 


X) 




CO ro 







in 


ro 


c-^ 


t^ 


W 








^00 rooo 


^ H 


tr^ in 




m 01 





in 




































t^ 


N 00 


in 


ro 


r>) 


M 





On 00 


t^ t-^vo >o vo 


in in 


in 


Ti- Tf 


M 




w 


(N H 


'^ 




•^ 


^ 




























rg 




ro 




On 




t^ 


„ 




00 vo 


in 


Tt- 


00 










Tt- 




ro 




n 




ro 


C^ 




irjVO 




in 


H 















ro 




ON 




CM 


in 


m 


VO 


ro 


-^ 


vo 





in 
































OJ 







^ 


t^ 


I'l 


ro 


C^ 








aoo 00 


C^ C~>vo vo vo 


in m ■<*• 


H 






04 (N 


H 


i-i 


•-1 


11 























73 



invoint^NN (3^. t^ 

OOVOOl-^C^-^ QtH 

NVO ihVO OICX) inON-'T 



00 vo -tf ro H o O O^co 00 t^ t^vo vo in m m 



ro 'D t^vo (3". ro in t^cx) ro rri ^j- 

ro i»- cMvovo romroc^vo vo rooo 

ro \r) If) i^Ot^ ror>.CMt^ro rooo ro 



00 vo 
0) invo 
T^ tN.'0 



vo 00 ■>!■ 
ro ro M 
vo in m c^ 



in ro ro Th 00 0^ 
t^ 04 ro C3n m mvo 
rooo rooo moo w t^ 



oovoinroo4HOO onoo 00 t^ tN.vo vo »/» 



mOmOinOmQinOinoinoinoo 
CJ ro ro ""J- "^ m mvO vO t> t>iOO <» O* a» w 



i 



•siaaHiW laHQNVH 



PINION 20. 



5 


to 00 W 


H 00 in -4- vo H 
00 (N w M a> fo o\ invo 
HinoN-^ vow t^inot^-* 


§ 


WOO 10 W w 

M M H M M 


<y,oo 0.V0 vovo ir> *n vi ^ "t -^ ffi tfi 


^ 


N in 


in H t^ cA m in t*i 

inHt^ ooCT Min NO 

OS Mvoo'OHooinNOMniHoe 


2 


s-s^^i^ss 


a> ONGO K^ c^vo vd »o«nio4"«i-4«n 


^ 


NO %^ 


00 NO sh w ^ 0^ 00 

w t^M inmoo 000 

0000 mt^<Nt^cn voTj-omt-t 




5rs^j?^2 


d OS O\oo t>H t^vd '<>^ ic in ^ 4- 4^ 



VO t>. 

vo in t^ 



fo m T}- 
vo rooo 
rr.oo ro 



vo in r^oo ^ H vo N 

VOt^'HOOOO OOmOn 

vo m M 00 VO m H onvo 



t^ ""i- w o 00 t^ t^*o mmiO'^Tt-'^mmcooN w 



momomomo mo mo mo mo 
w ro fo ^ Tf m mvo vo t^ c^oo 00 o\ Os o 



% 



^ 


rhm vo ^s0^l« t>»c6m 
10 HW com mHHoo mmHt^ 
M rt- V) ts.vo t^vo t>. CO c«» rooo in M 00 cooo m 


gs 


o^ fo ovvo ^ CO H a> ovoo t^ ts.vo vo vo m m r^ Ti- 


^ 


10 w 


"^ N m H H t^ VO 
m mo> r^M mrom-^ 
e*. vo ■<*• mvo ■<!i-oo •* co t^ n 00 


§■ 


w 10 
row 


HOOin-'i-NHOOs ovoo t^ «>. t>.vo vo m m -* 

N M M H M W M 


^ 




mm N -^N N.H N vomcj 

00 t>i tv. moo ""^ roTf- mvomoos 

m w 00 m w w mvo --j-osmM t^nvo m 




m t>. w Osvo m CO N H OS Ovoo t^ tv t^vo vo m m 

rOMWMWHHMMH 


a 


m 


vo ^< m H rooo oovoh^mmTj- MO^ 
vomt^H oorowvoforomovm ovh 
H 00 00 w m m N ovvo TfN 000 ^^meg w 


m 
m 


CO H 

M H 


OS i>.vo vommTj-ri-fococococow 01 w w n 


a 


M vo rt- mm 0^^0fO t^ t^ 
t^ vo m H 00 m N rovo CM 
m mvo -^ von t>«mrooi t^ioro 


v8 


m w 

M M 


00 t^vo vomm-^rj-Tj-fococofOfocM n w 


p. 


m 


(T) in m N 0\vo « ro N m h n -^oo 
rooo w CM iH -^ rovo 04 m m m m q 
CX3CMlHC^^r)O^T^ vorOO<X>vO'<^NOsC>.in 


m 

vo 




vo r"i O\oo C--VO mmm^'^'^coromcoN <n n 

M H M 






•s^^aHAi as^aNvw 



259 

PINION 20. 





i 




N mo^r^H oovom-^oo 
-^ CO ro t-H mvo H in M 
M ro ON wm mo^ro ->^vo 






-^0 t^mcoN ONOo 00 t^ j>sVO vo *o in in Tf 

NWMHMHHM 






xr 




00m H HT*-Nt^00 

CN(N 0. mvOH H-^ vo 
m-^vo rnoc^^N oovomr^ 


mmo 
m -<^ tN. ro 
(N 00 t^ 


s. 




0. c>>vo inm-rfTi-rororofOW N m w 


CM CM H H 




in 




in t^oo in cMOm c^iMino 
CM H incjNmHoo mmo 0\ t-^^o 


m CM ro 
t^ mvo 

Tj- (N ON 


m 
m 




00 t^vo m^'^'^rorororoc^ 04 w 


CM CM C^ M 




in 


ID 

m 

M 


00 


rt C7> rovo in'O CM 
win inm t^t-^ tj- 
t^r^ -^ONmMcx^vorow 00 


m m t~>. 

t^ '>*• CM 


S 






M 


C^vo "O inrt-Tj-ri-rororororotN 


M <N C-) CM 






10 

(N 


t^ 


t-^cM 00m CX3 voh cxamoit^ 
ininn mMt^ t^ mrfint^c^mrom 

t>. m ro moo rooo m h onvo tj- cm O Os"^ ■*• cm 


m 

vo 


C/2 


H 


O^oo t^vo mm'^^^rororororo 


01 M CM CM 


W 

W 


10 


10 


m t^ vo t>>oo m 

r>N M m ^ mm h 

m 00 roo^cMoomcMONC^mro 


ro m ro 
mvo (N CM 
M 00 ^ T^ 


a 


in 


N 


c>i t^ t^vo mm-^'^-^rororom 


ro CM (M OJ 




in 

00 


in 


CMt^ vomoiM 00 vo 
m-^ro mr<"0)ON(N HC^mt^ 
Nvo Thmc^Hvo McxD incM c>>t^m 


ro 00 m 1 


m 


Pi 
u 

C/3 


^ 




M o^oo r^^vo mm-^^'i-rororororocM cn 




to 




Tl- 


m mvO(N mONOo 
00 Tj-ro-^ rocor^^ 
CM cMm mHOomcj t~^vD n 



00 




00 




CM 0.00 t^vo \0 mm'^-^'^'^rorororoCM 




■<4- 


«n 


oo(N T^ln'^-^ M >oinc^t^(N 

in (N MD in in t^oo vo 00 m c^ cm t-^oo -^ 

ro t^ C^i m mvo 0. rooo tj-h o^mw 000 -^m 0\ 


m 

00 




o^ in (N Choo t>Nvo vo ininm^^^'i--"*- 


ro ro ro W 




10 


in 


CM 


M m ro t^m nti- ro 

t^ N vo m rooo vo vo ^o 

mmw Hrot^CMC^'<*-ot^mcM 


M moo 
moo r-« M 

^ ro H. 


8n 




g^ 


ro H Onoo t^^ ^ m m m -* Tf xi- 


■^ ro ro ro"" 




IT) 


in 

m 


H 


Tf r> CM mvo t^ ro On 
mMoo mt^NrxO -"S-wm 
CM CMVO mmr^M mtn t^roo t-^m 


\r)\C CM 00 
t^OO VO 00 
CM 00 m CM 


m 

ON 




M 


t^ 


T^ CM Onoo t^t>.ovo mmm->*-'Tj- 

H H tH 


TT ro ro ro 














•'•'•'"•■•*•■•*•*• 






•'••*'*'•'•**•••**** 






....,.,•. • 






•'•• ••• ..•.,.. . 






. '..',,'.'.'.... 













•*•••■•." *', 






8 


mo "^0 mo mo mo mo mom 
w m m Tf -^ in mvO vo t^ t>.c» 00 on On 


82g^ 

M W M M i 





'siaaHAV qaHQNViM 



26o 
PINION 20. 



r 


M VO -* in IT) On CO r^ t% «^ 
t^vo m Hioo lowrou-) n O 
»o 10^ ■* VOM t^ioroM t^ioro 

»n M 00 t^vO vd»o»r>'*'i--<i-cocoforo(nw cl w 
*4 H w 


8 


% 


VO « M 00 rooo H >o -* inoo ovo ><i- 


,S 


VO CJ O^oo t^vo ir)iO'<i--^TfThrorocr>cr;N n w 

H M H 


% 


roTj- m wvot>.t^ro t^oo m moo 

fOH IT) ooMDmmfom t^t^ o\ rr-, m 

VO CO t^ U-) 1000 mvomoou-)<n ^t^in-^ocxavo 

t^ CO M o\oo t^vo vd inio-^TJ-^T^cocorocow w 

M M M 


10 
. CO 


% 


00 T^co'^ rooot>.vo 
^ CN win inMooma c^vo <n t^ 


a 


00 "^ N c^cx) t^vo^o inin'^-!j-'<^'«^cococofON 

H H M H 



^ 


^o in 
W VO 00 


^ 0\ rovo 00 VO in (N '■J-vO co 

■<*• Oco-<j-(Nvoint^N invo oj 

in Ti-vo ON cooo ^ot^-^w 00'<J-HO^ 


^ 


OMn N 


o^oo t^vo VO ininin'<4-'^'<4-'<^cococoN 


^ 


rooo 
c^ 01 
CO ^ 


00 MvOfO^ro oOTj-in VO fovo 
00 t^vo inMco mrj-H cocot^ 
00 wvOHtr^co t^'<i-(N voroo 


8 


s^^r: 


00 00 t^vo VO ininin'<i--<}-T^rj-fococo 





VO H t>» 

VO tv. t>» 

VO VO in c^oo 



CO 0\ invo VO 00 M 
cove CO VO r>.oo CO 
coc^woo inHoovo 



VO T^ 
VO 00 

VO CO 



H ovoo 00 t^vo VO m m m "i- 



•^ VO t^ 

M VO C) 

t>. VO VO t>i 



00 in 
cooo -"i- 



t^ CO in CO N 
-<*• CO in VO o^ 

VO CO O 00 CO VO 



CO t^ in rhvo 

ro in m mvo 

00 cooo in ->*■ -<d-vo 



ro «>N t>. CO f^ ro 
CO H c>. t^ 0) ro 



VO 

VO 

ri-VO 



w ro in 

00 CO M 
M C0"0 



VO 00 01 ^ H VO rsi 
VO 00 w Ov o^vo O 
->*• incNOOVOQvoro 



ioO»nO»nO"~'Qino»noino»nooOO 
N CO CO ■«*■ '^ m inv5 vo t>, t^oo 00 0\ 0> O m m c*> 



% 



•siaaHAV aa^QNViAi 



26l 

PINION 20. 



10 10 



■<i-C>u-)iHoo incN OOu LocM On 



OMT) N M O^oo £■«= tN,vo iOLoiO^^^Tt-rororo(N 






Ti- 0) O ONOO !>. i>.vO O u-)in-<*-^'^^rnro 



M ro 
f^oo 



"Ot^Nino\o^ON 

vo 00 10 1000 un m^ O 



ro 


ro 
m>o CO 




00 ONVO 00 rOiOTfTht^ -*(-oOn 
lOOO- O^ro ro(N^-:^LO mcX3VD 
(NOOOOONMIO lOMt^TfuON-^l-OC^ 





01 M H 


Tf 


(N ONOO CO C^ t^VO "O LOLOlO^^^rO 


l^ 


10 

CO 


10 

(N 10 




LOVO iJ^ VO CJ VO rovo C^ lOOC 
MVO -"^Lor^ vot-^roNior^t^ro 
r-tvoinrnt^-oio ii">HOO>ocNf^roO 


H 


>0 H I>» 

(N (N M 


LO 


ro w ONOO 00 !>. C^VO VO 10 U-> LO Tj- -^ Ti- 





N 


(N 


(N On H t>i Th VO ■<*- 

rv.vor>. ioc>. On rooo 

in vo(N c^io-^cSiH oooovoLoro 


10 


0\ t^"0 


io-<l--<^rororoMWNCMWN'HHi-iMi-t 


% 


VO 
VO 




tJ- vc rovo l>.vo 0) 01 10 VO CO 
rh ror<~, t^iovo lOdO oovoro 
^ voroOoo.voiorO(N»H HVOio 


i. 
?. 


<»^0 


miO-<^-*rororO(NC^M(NCM(N(N -MM 





i 


ro LO CO 

rooo CO 

00 ro N 1000 ■* 


VO -:!- (N 0-. 
VO 00 T^ ro 
VO ro H 0- 


00 Tt- t^ 

LOOO T(- H 

t-^ 10 -^ ro 


IN 


ro N 

ro On 


»n 
10 


H 00 C^vo LO -"d- rj- 


■^ ro ro ro (N 


(N N N CN 


(N 


CM 

M M 


S- 


LO 

VO 00 


ro 
ro 
rooo 


ro (N 00 
VO On (N 
ro VO Th (N 


rovo VO 

(N VO <N 
CO VO 10 


Th 


M VO 

00 Tl- 
M 00 


vS 


CM OnOO VO VO 


LO '4- 


■^ Tf ro ro ro 


ro CM « c^ 


(N 


(N (N H 


^ 


VO 00 
•*vO (N 10 




LO ro -^vo 
(N ro 1- VO 
t--.ro t^ Tl- 


00 00 VO 
10 1000 ro 
N 00 r--vc 


VO^^ 

ro H 


^ 


ro 00 • VO 


10 LO 


Tj--^-^rorororocM n 


(N 


CM CM <N 


S- 


ro 

ro 

W CO 


<N VO 


M VO r^ ro 
ONvo ro 
VO ro f^ 


-+ M t^ 

On H rh 

LO (N M ONOO 


10 ro ro 
-"4- ro 10 
U-) ro M 


g. 


•<i- H Osoo t^'O iou->Tt--^Tj-rorororoN 

H M 


CI 


N W (N 








































OLOO>nO«nO»nQioOtoOLno "O 
(N N CO ro -"J- Tl- LO iOv5 VO t^ t^OO 00 ON 0> 


8 


2§S.! 





C/3 

w 
w 



\^ 



•^IHHHAV. aaHQNVW 



202 



PINION 20. 



in 


10 \0 Nr^ OOOOm vovo -^oo vo 
«M Ht-»inM0"O 100 "O fO (N 
\0 tv Th 1000 Noc row ost^u->^N M 


'i§$% 


s 


OS l^VO lO-^-*-mmfO(N N N N N 04 (N 


H M H M 


^ 


vo 00 M tr> fo 
Vi Tt (NVONOOiON OOVOTTfOOJ 


M 8sKlO 


£ 


00 t^vO »Or(--*^f<->corOfON N N N N 

Hi 


N H M ti^ 


CO 


tn ro tv vn vo M en ro>0 l>. ■* 1000 »n 
t^ CO ooinioroos ir>ro^r^(<os c^"0 Os m 
ro M m lovo oiOM ts.iow ooosomrocg ooot*» 


.ff 


H OS iS^vo irnTi^-^cnericncria cm n n 


« W M M 



NO »0 

m vo <N 

W 00 W M 



lOCO VO VCVCOONC^lOW Tl-00 
OS-'d-O t^lOM Geo C^iO-'i-W OCJO 



CM OS(30 t>.>0 u-)1^r^^^O'^^O^OCM (N e4 W O 05 



\r» N ro N looo w 00 >o m irjo ^^ os 

N 10 VOOOlO!>.t^(^in CX300MVO(M00C»H 

H 10 t*. 10 1000 w c>.roo t^i^.cN O OS r^MD co m O 
r^i O 00 t^VO lOiO'^-^rfromc^roW N N N N N 



fo 



N M VO t^ 

(N OSO O 

N vO O VO ro 



CO On M -^ ><^ CO 10 
r>. 10 N - osoo in ro w 



Osoo t>.vo vmoTj-Ti-Tj-rororofOC* w cm n n 



10 vo r^ H • o\oo t^ vc 00 ir> w in ^ c?^oo 
c^ M fOMioomt^ invo »h o co t^ O f^oo 
00 Os OS in -^so Os^omN os^slnroH o>t^'^oj 



c>oo t>.vo m m 



ro ro fo CO CO 



m tN vo t^oo in ro in fn 

m c^ (MinTh fOLOH invo cm n 

t>.vo in 00 fot^wooinojosc^inmwoovo-"*- 

in 0) o OS t^ rs,vo inin'^'<4-'<i-roroco(nrnN w w 



I in ro CM C50 in w 00 rovo w ■* m N O Os 

IN 00 Mooin'*--^MmromMC3s WMC^m 

V) j VO CO o mm mvo o m m t^ •>;»■ m o>vc m co o t^ •'^ 

'^ vd ro w Osoo f^vd vd in in -^ -^ ^cncn(v>rofnN « 



vo t^ 

vo in t>. 
vo ir^ t>. 



rn en ^ 
vo moo 
moo m 



vo in r>«oo rf H vo N 

VOI>.H0000 COhhOS 

vo m w 00 vo in H osvo 



t^ -* M o 00 t^ t^^ mmm-^'^'^cncnroc^ca c« 



0»oo»r>Oti^OV)OTnOi/^0>J^O»jOOOa. 
« N m m -"^ -"^ m mvo vo c^ N.00 00 o^ os o h w en 



8. 






•siaaHAv aa"aaNVK 



















253 


































PINION 


20 


















i 








^ 


OS 




■<:^ 


r^ 




tnvo 




N 




■* 




t^ 














lO 









to 




t^ 


l^ 




-i- 




tfS 


in 


t^ 




^ 


IT) 00 




ts, t^ 


•"^ OMO 




00 VO 


CO 


M 




00 


t^ 


■^ 


M 





Bs 


(D 6 


OM>.vO VO 


lO Tj- 


■* 


■^ 


CO 


CO 


CO 


CO 


CO 


(N 


N 


0) 


c^ 


CN) 






" 












































!N 


lO 0"j 


l_ 






^ 




N 


covO 






o 


tn 


in 


1 




in 






^ 


w m 


00 


to 


CO 


t^ 




VO 


in so 




Lf'j 


OS 


t^ 


M 







N 


-«*• IT 


M 


M CO t^ M 


C^ <N 


00 


lO 


CO 


H 




» 


lO 


cr 


M 




en 






































OS 




Th 


M 


ON 00 


t-svo 


lOtO^'<*-^COCOCOCO 


CO N 


PJ 


01 


01 






H 


'^ 












































l_l 


VO 


Tt- 




in 


in 






On 


CO 


t^ 




t^ 




t^ 












r^ 


VO 


m 




H 


00 




lO 


0) 


CO 


lO 




0^ 




() 














m 


u-)VO 


•<^ 




VO 


C4 




r^ 


in 


CO 


M 




r-N 


in 


in 





m 




. 
















. 


















M 




lO 


M 


d 00 


t>«vd VO VO 


lO 


-^ 


■^ 


^ 


CO 


CO 


CO 


CO 


CO 


CN 


(N 


01 






H 


'^ 


H 










































00 


ro 






r-- 


Th 




lO 


M VO 


CO 








00 












0) 


u~j ro 






t^ 






(N OO VO 


r^ 






in 


CO 


o 





U-) 


N 




-^ 


(N cnvo 


lo 


t^ Tl- 




» VO 


■^ 


CO 




Os 


to 




ro 






• 
































l-l 




VO 


C 


H 


a>oo t^vo VO 


u- 


lO -<4- 


rf 


-^ 


O") 


CO 


CO 


cr 


CO 


01 


N 






H 


■^ 


^ 










































Th 




lO 




00 


o 






in 




OS 




M 




OS 












DO 




-^ 




CO 








CO 




X) 




t^ 




VO 


o 







-^ 




c^ 




N lO 




lO 


w 


X) 


lO 


<N 




t^vo 


0) 




r^ 


0) 


ro 


• 




































M 




00 


rj- W 





(7.00 


t>,vd VO 


lO 


in 


•^ 


^ 


■^ 


Tt- 


CO 


co 


c; 


cr 


01 






IH 


H 


H 


l-l 








































M 


VO 


l_l 






M 




lOOO 


co lo 




tn 
















-^ lovo 


On 






t^ 




r^oo 


CO 


o 




rh 


tn 




o 





u-iVO 




H 


t^vo 00 


u- 




m 


M 00 


m 


CO 




OS lO 


01 




CO 


CO 






• 






























. 


H- 




OS lo c; 


M 


ON 00 


t^ t^vo VO 


tr> 


to 


-*• 


^ 


■Tf 


^ 


CO 


CO 


CO 


CO 






•^ 


M 


H 


^ 










































CO 


VO 




„ 








M 


vn 


„ 




CO 




o 














CO 


CO 




VO 






lO Tt-vO 


(N 




M 




CO 





o 




>0 






lO CO -^vo 




Tl- 




VO 


w 


OSVO 


-^ N 00 


tn 


01 


Tj- 


CD 






































l-l 




M 


VO 


■^ (N 


OnOO t> t>.vo VO 


in 


to Tf 


rt- 


^ 


^=1- 


CO 


CO 


CO 






(N 




H 


•^ 


M 






































I^ 




^ 




cooo 




lO 


r^ 




f^ 




M 




H 












lO 


lo 


00 




N 


r>) 




(N 


OS 




CO 




OS tnvD 








U-) 






DO 


(M 


H 


>0 On '^ 




VO 


C>) 




t^ lO 


t^ 


^ 


in 


ro 










































N 00 


lO 


w 


H 
w 1-1 


OS 00 


t^ VO VO VO 


lO lO lO 


■^ 


-^ 


■^ 


CO 


CO 










VO 




H 


lO CO CO 




VO 




t^ in 


CO 




(N VO VO 










VO 






■<*■ 


n- 


to 




VO 


lO 


Tt- in 


t^ 




t^VO 


r^ 




CO 




VO VO 




lO M 


00 lO 


co 






00 


tvvO 


lO 


-^ 


M- 


OJ 


IH 





% 


t^ lO 


■"I- 


■<*■ 


CO CO <N N 


N 


N 


N 


•-' 


M 


^ 


H 


'-' 


'-' 


M 


'-' 


^ 




lO 








t>. 


CO lO 


CO 






00 


OS 




r-N 




„ 










t>. 




VO 




CO 


lOVO 


0) 


0) 


m 




VO 


fx to 


lO 


r^ 


CO 








1?^ 


00 


CO 0» 


U-) OMO 


H 00 VO 


'^ 


c^ 


H 


OS 00 


t^vo 


lO 


■"ii- 


CO 


0) 


ID 

•>4- 


t^vO 


lo '^ cr fo 


CO N 


N 


« 


N 


« 


'-' 


M 


H 


^ 


H 


" 


H 


^ 








CO 




lOOO 


H 


o 


N 




CO tvOO 


rr 


CJ 




00 VO 






m 




en 




t^OO 


00 




OS 




CO 00 


lO 


3; 


T^ 


in 


ctn m 






CO 


f^ 




00 




coco 


m H 


CvVO 


»o 


CO 


H 





00 


t^ to Tl- CO 


a 


00 


t^min-^cororON 


w 


M 


01 


M 


(N 


M 


H 


" 


M 


H 


^ 




i 


to f5 


lo 6 in d "^ d 


to d 


lo d 


in 


i 


lO 


8 


d 


d 


d / 






w 


CO ro ■^ "^ lO m 


o 


VO 


t^ r<soo 00 


On 




0) 


00 




































M 


M M V 





C/3 



•SiaaHAV 'JHNGNVIV 



t/3 

•J 

w 

I— t 

p 

w 

H 



264 
^INION 20. 



vo 00 Tf H M rovo 0\ 

VO -"I- M 00 t>.VO 10 •^ fO <S N O 



CO CO N W 0) « 



t>* in Ti- r^oo 1^00 M t^ irjoo 

10 lOt-s loiOt>-(N 00 00 MlOWMCa 

t^ -* moo ro t^ ^ w o CJ>oo vo ir)io->^fniM Mf> 



vOio-<i-fororoM w (N w 



lO CO 

00 m m 



N O -<*• 

c^ 10 m H 



\r) T*-<0 00 fO fO 

t^vo vo r^ vo 10 »o 
00 c^vo in 10 fo w M 



t^vo in-^romcoN N N cs 



in M M vo 

N vo »n t^ H vo CO 



00 t^ N 

in CO in vo 
^> in CO oj o 



iH covo in o\ 

Th ro fO in ^NVO 
Oioo r^vo in CO cj 



00^ in-<^'<*-cococoN 



OJ (N <N W ;h 



■^ t~>. vo t^ in 1-1 

^N Hin vo(N c^iO'^j-WK 

o^ t^vo in^^cococooi N c5 ci ci 



■^ vo -^ 

C>i ro 00 

00 00 vo in CO 



w -n CO in 
in t^ c^ ro '^ in 

t-^00 in moo CO o^ m (N 



in t-^ Tj-vo (N N in 
c» ^ CO o^vo in in t>. CN 
t^vo -^ 0) M o o^. t^vo in 



On t^vo mTf^rocorocoN n (N cn w w* m 



00 



in 



vo 
invo M CO 
N vo cj 00 in (N 



l^ CO o On in 

^.Jjt^coM omM 
00 vo T^ CO (M H ON r^vo 

O 00 tvvo in-<^-<i-cococoroM(NoiNcgcJMMM 



00 in 
in '^vo 



H T^ 



N t^ 00 in in o 
M T^ vo in '^^ t-^ ro 
oovomcowooor^f in 
c^ t>.vo in m Ti- Ti- fo fo ro CO (N c^ -'-'-•-' ' * ' *^ 



N 0) N M H 



vo 



CO CO 
CO vo 
cooo CO 



o 00 
On 0) 

vo '^l- N 



covo vo 

CM 'O 0) 
00 vo LO Tj- 



N ONOO vovo in-'^'^TfrococorocN 



M vo 

30 ^ 

M 00 

CJ CN W (N N H 



in 00 t^vo CO in (N ^ 00 COOO in H nvo 

t>« c^ in w covo M vo (N ONvo Tj- M TO S in f^ M o^ 

N o 00 c-^vo inm-^^cocococococi c^ m ci eg m 



Qw^OmcmomomoinoinOmOO 
|«c>jcoco-<i-Tj-in mvo vo t> c>»oo 00 on on o m 



S7a3HA\ Tf^THaNVK 



265 



/ABLE FOR MAKING THE UNIVERSAL TAPS, 
WITH THE MOST SUITABLE PROPORTIONS 
REQUISITE FOR GOOD WORKING TAPS 
USED BY HAND. 

From X ^^ A ^^^ head is turned the same size as the 
screw; the ^, and all above, to pass through, the holes 
screwed. As the same table shows the size of tap and bot- 
tom of screw, the workman will be enabled to make the 
tapping holes a size that will insure a full thread. The bot- 
tom of screw will give the size for drills, bits, etc. 



c3 



X 






1^ 

Vs. 

iX 






o o 



lb 



% and 



3 2 

and 



and 

5/ 



T^ and 6, 
}i and -3^3 

I and §-^ 



2X 
23/ 



3^/ 

4 

4X 

4/2 

5 

5X 
6 

6^ 

7 



1/8 
I ^- 



2 

2>^ 
2X 
2^ 
2>^ 
2^ 
3X 

3^ 
3^' 

4X 






ffi 



7 . 
] 6 



i! 

1« 
X and j-ig- 



-g Wheels for cutting 
the screws. 



^-^ 



I 



20 

18 
16 



14 
12 
12 
II 
II 
10 

9 

8 

7 
7 
6 



^ ^ 



40 
40 
45 



i . 




S ii 


E! 


53.2 


^0 


■^-^ 


c: 


>— 1 


Ph 


80 


20 


80 


20 


80 


20 



c/2 



100 

90 
90 



Simple wheels. 



?o 






20 






?o 






70 






?o 






?o 






'^n 






?,o 






?o 






?o 






?o 













140 

12a 

120 

no 

no 

100 

90 

80 

70 

70 

60 



266 



Table for Making the Universal 


Taps- 


-« (Continued.) 


Q. 

5 


"2-^ 

gi 






•0 


^ 

G 


Wheels 
for cutting th^ 


^ 


■5 ^ 








^ 


^ S 


screws. 


o 


^_ c 


•£3 




Head lengt 
square. 


^ a. 




1 

s 


Bottom o 
or tappi 


1 


St.. 




13 




I'A 


*32 


7^ 


43/ 


iH 


6 


20 


60 


iH 


9 


S'A 


iVi 


5 


20 


50 


13/ 


iVB and e^i 


9% 


s% 


iH 


5 


20 


50 


I?^8 


ijl 


10 


b% 


I'A 


4J^ 


40 


90 


2 


i|^ andi,% 


11 


63/ 


i^ 


A% 


40 


90 


2>i 


1 34: and 3^ 


11;^ 


7X 


1% 


A% 


40 


^ 


2X 


i^and-i-L 


12 


P4 


in 


4 


40 


80 


zH 


26\- 


12% 


«K 


iH 


4 


40 


80 


2% 


2-,% 


n 


I03/ 


iH 


4 


40 


80 


zH 


2-4 


13 


QX 


13/ 


4 


40 


80 


2 3/ 


2^ 


13;^ 


9^ 


lU 


■3^2 


40 


70 


zVi 


2/3 


13/2 


10 


1% 


3/5 


40 


70 


3 


2>^ 


14 


10 


2 


3K 


40 


70 



UNIVERSAL GAS-PIPE THREADS. 



Diameter. 



Wheels for Cuttinc, Etc. 



Man- 
drel. 



Interme- 
diate. 



Pinion. 



Screw. 



Pitch. 



t%, and all above 
I 

K 

M 

Small brass tube . . 



85 
20 
20 

30 

30 



80 



20 



60 



20 
20 



120 
140 
140 

85 
120 



11.294 
14. 

14. 
18.412 

24. 



HOW PUMICE STONE IS MADE. 

Pumice stone is now prepared b)/- molding and baking a 
mixture of white feldspar and fire-clay. This product is said 
to have superseded the natural stone in Germany and 

Austria. 



267 
NOTES ON THE WORKING OF STEEL. 

1. Good soft heat is safe to use if steel be immediately 
and thoroughly worked. 

It is a fact that good steel will endure more pounding than 
any iron. 

2. If steel be left long in the fire it will lose its steely na- 
ture and grain, and partake of the nature of cast iron. 

Steel should never be kept hot any longer than is necessary 
to the work to be done. 

3. Steel is entirely mercurial under the action of heat, 
and a careful study of the tables will show that there must of 
necessity *"»e an injurious internal strain created, whenever 
two or m(y^e parts of the same piece are subjected to dif- 
ferent temperatures. 

4. It follows that when steel has been subjected to heat 
not absolutely uniform over the whole mass, careful anneal- 
ing should be resorted to. 

5. As the change of volume due to a degree of heat in- 
creases directly and rapidly with the quantity of carbon 
present, therefore high steel is more liable to dangerous in- 
ternal strain than low steel, and great care should bo exer- 
cised in the use of high steel. 

6. Hot steel should always be put in a perfectly dry jJace 
of even temperature while cooling. A wet place in the floor 
might be sufficient to cause serious injury. 

7. Never let any one fool you with the statement that his 
Steel possesses a peculiar property which enables it to be 
** restored " after being " burned; " no more should you waste 
any money on nostrums for restoring burned steel. 

We have shown how to restore " overheated " steel. 

For " burned '* steel, which is oxidized steel, there is only 
one way of restoration, and that is through the knobbling fire 
or the blast furnace. 

" Overheating '* and " restoring " should only be allowable 
for purposes of experiment. The process is one of disintegra- 
tion, and is always injurious. 

8. Be careful not to overdo the annealing process; if car- 
ried too far it does great harm, and it is one of the commonest 
modes of destruction which the steelmaker meets in his daily 
troubles. 

It is hard to induce the average worker in steel to believe 
that very little annealing is necessary, and that a very little 
is really more efficacious than a great deal. 



268 



WEIGHT AND NUMBER OF SQUARE NUTS IN A 
BOX OR KEG OF 200 POUNDS. 



AMOUNT OF 



HEAT REQUIRED 
WROUGHT IRON. 



Width. 


Thick- 


Hole. 


Size of 


No. in 


Weight 




ness. 




Bolt. 


200 lbs. 


of Nut. 


% 


X 


7-3-^ 


X 


14,844 


lbs. 


'A 


S-16 


9-32 


5-16 


7,880 




K 


rs^ 


11-32 


V, 


4,440 




% 


7-16 


13-32 


7-16 


2,732 




% 


A 

A 


7-16 
7-16 


\y. 


2,450 
1,816 




\% 


% 


% 


9-16 


1,390 




lYs 


A 


9-16 


[ A 


1,174 


.17 


1% 


H 


9-16 


898 


•23 


ifi 


U 


21-32 


\A 


662 


•3 


1% 


U 


21-32 


538 


•37 


1% 


A 


25-32 


i yA 


392 


.51 


lU 


A 


25-32 


i /' 


326 


.61 


iK 


I 


^ 


r I 


304 


.66 


2 


I 


^ 


224 


.89 


2 


lA 


15-16 


^>^ 


214 


•93 


2X 


iV, 


15-16 


152 


1.32 


2X 


iX 


I 1-16 


-iX 


143 


1.4 


^'A 


iX 


I 1-16 


108 


1.85 


2% 


I A 


I 3-16 


I^ 


83 


2.41 


3 


lA 


I 5-16 


I>^ 


65 


31 


3X 


lA 


I 7-16 


I>^ 


51 


4- 


3A 


iV 


I 9-16 


iX 


42 


4.8 


z% 


lA 


I 11-16 


lA 


32 


6.3 


4 


2 


I 13-16 


2 


27 


7-4 


4 


2% 


lyk 


2M 




7H 


4X 


2% 


2 


2X 




8X 


4X 


m . 


2y% 


2>^ 




8X 


^A 


2y2 


2% 


2>^ 




lOK 


4'A 


2^ 


2 7-16 


2^ 




13X 


5 


3 


2 11-16 


3 




14 



TO MELT 



The temperature necessary to melt Nvrought iron lies 
between 4,000^ and 5,000^ F., and even ai that tremendous 
heat, wrought iron is only rendered fluid by ihe addition of a 
small amount of aluminum. 



269 

WEIGHT AND NUMBER OF HEXAGON NUTS IK 
A KEG OR BOX OF 200 POUNDS. 



Width. 


Thick- 


Hole. 


Size of 


No. in 


Weight 




ness. 




Bolt. 


200 lbs. 


of Nut 


^ 


y* . 


7-32 


^. 


17,332 


lbs. 


Vi 


5-16 


9-32 


5-16 


8,964 




H 


n ^ 


11-32 


/8^ 


5,016 




'A 


7-16 


13-32 


7-16 


2,988 




Vs 


'A 


7-16 


^- 1/ 


2,674 




I 


A 


7-16 


( 72 


2,160 




1% 


9.16 


A 


9-16 


1,445 




1% 


A 


(^-16 


f >^ 


1,310 


"Vii 


1% 


V% 


9-16 


1,028 


.2 


iX 


'i 


9-16 


) 


920 


.22 


iVi 


i 


21-32 


\ 3/ 


752 


% 


VA 




21-32 


f ^ 


510 


1% 


A 


25-32 


[ % 


450 


.44 


1% 


I 


25-32 


428 


.47 


i^ 


I 


% 


r 

K ■ 


372 


•54 


iK 


lA 


Vs 


P , 


336 


.6 


2 


iX 


15-16 


I>^ 


211 


•95 


2'/ 


I A 


I 1-16 


IX 


259 


1.26 


2/2 


iK 


I 3-16 


1/8 


119 


1.68 


2% 


lA 


I 5-16 


^y^ 


88 


2.27 


3 


iK 


I 7-16 


IH 


69 


2.9 


3X 


lA 


I 9-16 


I^ 


56 


3.6 


3>^ 


2 


I II-16 


I^ 


44 


4-6 


1% 


2 


i 13-16 


u 


43 


4.7 


4 


2 


I 13-16 


(^ 


29 


6.9 


Z% 


2>^ 


I^ 


2>^ 




S% 


3X 


2^ 


2 


2X 




^% 


4 


2/8 


2}i 


2^8 




6X 


aV. 


2;^ 


2X 


2X 




1% 


AV2 


2^ 


2 7-16 


2H 




9% 


aK 


3 


2 II-16 


3 




ii/i 



HOW TO PREVENT GEAR TEETH FROM BREAKING. 

Gear teeth generally have one corner broken off first, after 
which they rapidly go to pieces. This may be avoided and 
the teeth made much stronger by thinning down the edges 
with a file, thereby briiic:mg the whole strain along the centre 
of the tooth. jear teeth fixed this way will not break uuleSf 
the strain be sufficient to br ^ak off the v/Jiole tootlu 



270 

NUMBER OF LIGHTS OF WINDOW GLASS IN A 
BOX OF 50 FEET. 



Size. 


No. 

Lights. 


Size. 


No. 

Lights. 


Size. 


No. 
Lights, 


6x 8 


150 


28 


16 


5? 


5 


7x9 


115 


30 


15 


30x38 


7 


8x10 


90 


18x22 


18 


40 


6 


II 


82 


24 


17 


42 


6 


12 


75 


26 


16 


44 


6 


13 


^9 


1 28 


14 


^^ 


5 


14 


64 


30 


14 


48 


5 


9x12 


67 


32 


13 


50 


5 


13 


62 


20x26 


14 


52 


5 


14 


57 


28 


13 


54 


4 


15 


53 


30 


12 


32x40 


6 


10x13 


56 


32 


II 


42 


6 


14 


5? 


34 


II 


32x44 


5 


IS 


48 


36 


10 


4^ 


5 


16 


45 


22x28 


12 


48 


5 


11x14 


47 


30 


II 


50 


5 


15 


44 


32 


10 


52 


4 


16 


41 


34 


10 


5^ 


4 


18 


39 


36 


9 


56 


4 


12x15 


40 


38 


9 


34x44 


5 


16 


3S 


24x30 


10 


4^ 


5 


18 


34 


32 


10 


48 


5 


20 


30 


24x34 


9 


50 


4 


13x16 


35 


36 


9 


52 


4 


18 


31 


38 


8 


54 


4 


20 


28 


40 


8 


5^ 


4 


22 


25 


26x32 


9 


g 


4 


14x18 


29 


34 


8 


4 


20 


26 


3^ 


8 


36x46 


4 


22 


24 


38 


7 


48 


4 


24 


22 


40 


7 


50 


4 


15x18 


27 


42 


7 


52 


4 


20 


24 


44 


6 


54 


4 


12 


22 


28x36 


7 


'•6 


4 


24 


20 


38 


7 


58 


3 


26 


19 


40 


7 


36x60 


3 


16x20 


23 


42 


6 


62 


3 


22 


21 


44 


6 


64 


3 


24 


19 


46 


6 


38x46 


4 


a6 


17 


48 


«; 


48 


4. 



^y i 



NUMBER OF LIGHTS OF WINDOW GLASS IN A 
BOX OF 50 FEET Continued. 



Size. 


No. 
Lights. 


Size. 


No. 

Lights. 


Size. 


Now 
Lights 


50 


4 


60 


3 


66 


3 


52 


4 


40x62 


3 


68 


3 


54 


4 


64 


3 


70 


2 


56 


3 


66 


3 


44x54 


3 


5^ 


3 


40x68 


3 


5^ 


3 


60 


3 


70 


3 


5^ 


3 


62 


3 


42x50 


3 


60 


3 


64 


3 


52 


3 


62 


3 


66 


3 


54 


3 


64 


3 


40x48 


4 


5^ 


3 


66 


2 


50 


4 


58 


3 


68 


2 


52 


3 


60 


3 


70 


2 


54 


3 


62 


3 


72 


2 


56 


3 


64 


3 







COMBUSTIBILITY OF IRON PROVED. 

Combustion is not generally considered one of the prop- 
erties of iron, yet that metal will, under proper conditions, 
burn readily. The late Professor Magnus, of Berlin, Ger- 
many, devised the following method of showing the combus- 
tibility of iron : A mass of iron filings is approached by a 
magnet of considerable power, and a quantity thereof is per- 
mitted to adhere to it. This loose, spongy tuft of iron pow 
der contains a large quantity of air imprisoned between its 
particles, and is, therefore, and because of its extremely com- 
minuted condition, well adapted to manifest its combustibil- 
ity. The flame of an ordinary spirit lamp or Bunsen burner 
readily sets fire to the finely divided iron, which continues to 
burn briUiantly and freely. By waving the magnet to and 
fro, the showers of sparks sent off produce a striking and 
brilliant effect. 

The assertion that iron is more combustible than gun- 
powder, has its origin in the following experiment, which 19 
also a very striking one: A little alcohol is poured into a 
saucer and ignited. A mixture of gunpowder and iron filings 
is allowed to fall in small quantities at a time into the flame 
of the burning alcohol, when it will be observed that the iron 
will take fire in its passage through the flame, while the gun* 



272 

powder will fall through it and collect beneath the liquid 
alcohol below nnconsumed. This, however, is a scientific 
trick, and the experiment hardly justifies the sweeping asser- 
tion that iron is more combustible than gunpowder. The 
ignition of the iron under the foregoing circumstances is due 
to the fact that the metal particles being admirable con- 
ductors of heat, are able to absorb sufficient heat in their 
passage through the flame — brief as this is — and they are 
consequently raised to the ignition point. The particles of 
the gunpowder, however, are very poor conductors of heat, 
comparatively speaking, and, during the exceedingly brief 
tmie consumed in their passage through the flame, they do 
not become heated appreciably, or certainly not to their point 
of ignition. Under ordinary circumstances, gunpowder is 
vastly more inflammable than iron. 

Another method of exhibiting the combustibility of iron, 
which would appear to justify the assertion that it is really 
more combustible than gunpovvder, is the following: Place 
in a refractory tube of Bohemian glass a quantity of 
dry, freshly-precipitated ferric exide. Heat this oxide to 
bright redness, and pass a current of hydrogen through the 
tube. The hydrogen will deprive the oxidt of its oxygen, 
and reduce the mass to the metallic state. If, when the 
reduction appears to be finished, the tube is removed from 
the flame, and its contents permitted to fall out into the air 
it will take fire spontaneously and burn to oxide again. 
This experiment indicates that pure iron, in a state of the ex- 
tremest subdivision, is one of the most combustible sub- 
stances known — more so, even, than gunpowder and otrier 
explosive substances which require the application of con- 
sideraole heat, <^r a spark, to ignite them. 

HOW IRON BREAKS. 

Hundreds of existing railway bridges which carry twenty 
trains a day with perfect safety would break down quickly 
with under twenty trains an hour, writes a British civil en- 
gineer. This fact was forced on my attention nearly twenty 
years ago, by the fracture of a number of iron girders of 
ordinary strength under a five-minute train service. Simi- 
larly, when in New York last year, I noticed, in the case of 
some hundreds of girders on the elevated railway, that the 
alternate thrust and pull on the central diagonals from trains 
passing every two or three minutes had developed a weak- 
ness which necessitated the bars being replaced by stronger 
ones, after a verv .'^hort service. Somewhat the same thing 



273 

I -. iv be done r'^cently witha hridije ovt-i th^ river Trent, 
but, the tiaiii service being sn^all, the life of I he bars was 
measured by years instea I of months. If ships v^'ere ahvays 
among great waves the number going to the bottom would 
be largely increased. It appears natural enough to every one 
thr.t a ]^iece, even of the toughest wire, should be quickly 
broken if bent back and forward to a sharp angle; but, per- 
haps, only to locomotive and marine engineers does this ap- 
pe^nr equally natural that the .same results would follow in 
ti:re if the bending were so small as to be quite imperceptible 
to the eye. A locomotive crank axle bends but one eighty- 
fourih of an inch, a straight driving-axle a still sn aller 
amount, under the heaviest bending stresses to which they 
a: e subject, and yet their life is limited. During the year 
I CS-^ one iron axle broke in running, and one in fifteen was 
renewed in consequence of defects. Taking iron and steel 
axles together, the number then in use on the railways of the 
United Kingdom was 14,847, and of these 911 required 
renewal during the year. Similarly, during the . past 
three years, no less than 228 ocean steamers were disabled 
by broken shafts, the average safe life of which is said to be 
about three or four years. Experience has proved that a 
very moderate stress, alternating from tension to compres- 
sion, if repeated about 100,000,000 times, will cause a frac- 
ture as surely as bending to an angle only ten times. 

VALUE OF EMERY WHEELS. 

The increased quantity and quality of work that goes out 
of the modern machine shop is due to the skillful use of solid 
emery wheels. A grain of sand from the common grind- 
stone, magnified, would look like a cobble stone, a fracture 
of which shows an obtuse angle, w^nereas a grain of ( orun- 
dum or emery would look like a rhomboid, always l)reak- 
ing with a square or concave fracture. No matter how much 
it is worn down in use, it does not lose its sharpness ; hence 
it is evident that the grindstone rubs or grinds and heats 
the work brought in contact with it, while the corundum, or 
emery wheel, -"ith its sharp, angular grit, cuts like a fde or 
angular saw. 

There are two general classes of emery wheels in the 
market — one class of wheels has the grains of emery joined 
and consolidated by a pitchy material, as rubber, linseed oil, 
shellac, etc. These must run at a high speed to burn out the 
cementing material by friction, loosening the worn*out grains, 
and thus revealing new cutting angles. These are "tni-porous 



an 

wheels. Truing up this class of wheels is done with a dia« 

mond tool. 

The other class consists of two kinds, one made by mix- 
ing the emery with a mineral cement and water into a paste, 
which will harden and bind the grains together ; the other 
kmd, by mixing the emery with a mineral flux or clay, mold- 
ing into shape, and burning in a muffle at a high tempera- 
ture. These are porous wheels, in which the grains of emery 
are held together by matter having affinity therefor. This 
class of wheels, unlike the grindstone, has sharp grains of 
emery bedded together among matter which, in some cases, 
is as hard and sharp as the emery itself. Such wheels cut 
very greedily, and do not need to be run at any particular 
speed. 

The dresser, made of hardened steel picks, is the proper 
tool for truing up this class of wheels. 

Manufacturers in metal goods aiming at reducing the cost 
of production, would do well to look into the adaptability of 
the solid emery wheels or rotary file, and other labor-saving 
machinery, before deciding on reducing labor wages. 

THE SECRET OF CAST STEEL. 

The history of cast steel, remarks a contemporary, pre- 
sents a curious instance of a manufacturing secret stealthily 
obtained under the cloak of an appeal to philanthropy. The 
main distinction between iron and steel, as most people know, 
is that the latter contains carbon. The one is converted into 
the other by being heated for a considerable time in contact 
with powdered charcoal in an iron box. Now, steel thus 
made is unequal. The middle of a bar is more carbonized 
than the ends, and the surface more than the center. It is, 
therefore, unreliable. Nevertheless, before the invention of 
cast steel, there was nothing better. In 1760 there lived at 
Attercliffe, near Sheffield, a watchmaker named Huntsman. 
He became dissa!tisfied with the watch-spring in use, and set 
himself to the task of making them homogeneous. "If," 
thought he, "I can melt a piece of steel and cast it into an 
ingot, its composition should be the same throughout." He 
succeeded. His steel sooii became famous. Himtsman's 
ingots for fine work were in universal demand. He did not 
call them cast steel. That was his secret. About 1780a 
large manufactory of this peculiar steel was established a^ 
Attercliffe. The process was wrapped in secrecy by ever* 
means within reach. One midwinter night, as the tall chim, 
*»eys of the Attercliffe steel works belchSi forth their smoke 



H traveler Smocked at the gate. It was bitterly cold, and the 
snow fell fast, and the wmd howled across the moat. The 
stranger, apparently a plowman or agricultural laborer seek- 
ing shelter from the storm, awakened no suspicion. Scan- 
ning the wayfarer closely, and moved by motives of humanity, 
the foreman granted his request, and let him in. Feigning 
to be worn out with cold and fatigue, the old fellow sank 
upon the floor, and soon appeared to sleep. That, however, 
was far from his intention. He closed his eyes apparently 
only. He saw workmen cut bars of steel into bits, place 
them in crucibles, and thrust the crucibles into a furnace. 
The fire was urged to its extreme power until the steel was 
melted. Clothed in wet rags to protect themselves from the 
heat, the workmen drew out the glowing crucibles and 
poured their contents into a mold. Mr. Huntsman's factory 
hsid notiiing more to disclose. The secret of making cast 
Jteel had been discovered. 

IRON AND STEEL MAKING IN INDIA. 

Indian Engineerings in a recent issue, gives a most 
interesting account of the manufacture of iron and steel in 
India, which we reproduce below: 

Notwithstanding the simplicity of their processes, the 
iron turned out by the natives is of superior quality, and is 
selling very cheaply; so, for instance, a mound of horseshoes 
sells at Rs. seven, and of clamp iron Rs. six-eighths. These 
low prices are accounted for by cheap fuel, the rich ores, the 
miserably cheap labor, and the absence of managing expense.. 

There are reasons to believe that " Wootz " (Indian 
cast steel) has been exported to Asia Minor more than 2,000 
years ago; how long, however, its manufacture has been 
commenced, cannot be traced. 

The following is a description of the method for making 
" Wootz " employed by the natives at Hyderabad. 

The minute grains or ' scales of iron are diffused in a 
sandstone-like gneiss or mica schist, passing into a horn- 
blende slate. These rocks are excavated with crowbars, and 
then crushed between stones; if hard, this is done after prelim- 
inary roasting. 

The ore is then separated from the powdered rock by 
washing. This was at a village called Dundurti, but the pro- 
cess of manufacture was the same as that at Kona Samun- 
drum, twelve miles south of the Godavari, and twenty-five 
from Nirmal, which has been described by Dr. Voysey. The 
furnace was made of a refractory clay, derived from decern- 



276 

posed granite and the crucibles are made of the same, ground 
t# a powdei together with fragments of old furnace and 
broken crucibles kneaded up with rice, chaff and oil. He 
states that no charcoal was put into the crucible, but some 
fragments of old glass slag were. A perforation was made 
sn the luted cover. Two kinds of iron, one from Mirtapalli 
and the other from Kondapore, were used in the manufacture 
of the steel. The former was made from magnetic sand, 
and the latter from an ore found in the iron clay (? laterite) 
rlwenty miles distant; the proportions used of each were 

This mixture being put into the crucible in small pieces, 
the fire was kept up at a very high heat for twenty-four hours 
by means of four bellows, and was then allowed to cool 
down. Cakes of steel of great hardness, and weighing on the 
average i% lbs., were taken from each crucible. They were 
then covered with clay and annealed in the furnace for twelve to 
dxteen hours; then cooled, and, if necessary, the annealing was 
repeated till the requisite degree of malleability had been 
obtained. The Telinga name for this steel was " Wootz," 
and " Kurs" or cake of it, weighing no rupees, was sold on 
the spot for eight annas. The daily produce of a furnace 
was 50 seers, or in value Rs. 37. 

Also Mysore is a country where the manufacture of iron 
and steel by the natives was of great importance owing to the 
excellent quality of its produce. 

^The iron was made from black sand, which the torrents, 
formed in the rainy season, brought down from the rocks. 
The furnaces in the Chin-Narayan Durga taluk were on a 
small scale, the charge of ore being 42^ pounds, from which 
about 47 per cent, of the metal was obtained. Work was 
carried on for only four months, the smelters taking to culti- 
vation during the remainder of the year. The stone ore was 
smelted in the same way as the iron sand, but the latter, it is 
said, "was alone fit for manufacturing into steel. There were 
in this vicinity five steel forges, four in the above taluk, and 
OUe at Devaraya, Durga. 

The furnace, of which a figure is given by Buchanan, con- 
sisted of a horizontal ash-pit and a vertical fire-place, both 
sunk below the level of the ground. The ash-pi': was about 
three-fourths of a cubit in width and height, and was con- 
nected with a refuse pit into which the ashes could be drawn. 
The fire-place was a circular pit, a cubit in width, which was 
connected v/ith the ash-pit, being from the surface of the 
ground to the bottom two cubits in depth, A screen or mud- 
wall five feet high, protected the beliows-man from heat and 



sparks. The bellows were of the ordinary form, a conical 
leather sack with a ring at the top, through which the opera- 
tor pasr^ed his arm. 

'The crucibles, made of unbaked clay, were conical in form, 
and of about one pint capacity. Into each a wedge of iron 
and three rupees' weight of the stem of the Cassia Auricii- 
lata and two green leaves of a species of convolvulus or Ipo- 
maia were put. The mouths of the crucibles were then 
covered with round caps of unbaked clay, and the junctures 
well luted. 

They were then dried near the fire, and were ready for the 
furnace. A row of them was first laid round the sloping 
mouth of the furnace; within these another row was placed, 
and the center of the dome, so formed, was occupied by a; 
single crucible, makmg nfteef. ii: :-!i 

The crucible opposite the bellows was then withdrawn, 
and its place occupied by an empty one, which couid be 
withdrawn in order to supply fuel below. The furnace, being 
filled with charcoal, and the crucibles covered with the same, 
the bellows were plied for four hours, after which the opera- 
tion was completed. When the crucibles were opened, the 
steel was found melted into a button with a sort of crystalline 
structure on its surface, which showed that complete fusion 
had taken place. These buttons weighed about twenty-four 
rupees. There were thirteen men to each furnace, a head 
man to i^nake and fill the crucibles, and four relays of three 
men each, one to attend the furnace, and two for the bel- 
lows. 

P2ach furnace manufactured forty-five pagodas' worth of 
X, 800 wedges of iron into steel. The net profit was stated 
to be 1,253 fanams, but into the further details as to cost it 
is not, perhaps, lecessary to enter. The total production of 
steel in this vicinity was estimated to be 152 cwt. , or about 
;^300 per annum. 

The principal sources of the ores were the magnetic sand 
found in rivers, and the richer portion of the laterite. 

THE FLASH-POINT OF VARIOUS HYDRO- 
CARBONS. 

The following table gives the temperature at which 
various hydrocarbons give off inflammable vapors: 

Flajih Fire 

Open Test. Point. Point. 

Brandy, as usually sold retail 69 F. 92 P\ 

Whisky, *' '* 72 96 

Gin, ** " 72 loi 



278 ^^ 

Flash File 

Fire Test. Point. Point. 

Petroleum (ordinary American lamp oil) 73 104 

Saxoline no 150 

Ordinary high-test Petroleum iic-120 140-160 

Crystal Oil 150 180 

Downer's Oil , 270 310 

Mineral Sperm 310 330 

HOW BREAKS IN SUBMARINE CABLES AR?: 
DETECTED AND REPAIRED. 

The following is an account of how submarine cables art 
found and repaired at an immense depth: 

The break, which the " Minia " was sent to repair, 
occurred early last summer. The officers of the company 
first located the distance of the break from the stations on 
shore, on each side of t'^e ocean. The details of the instru- 
ment by which this is done are not easily described, though 
easily understood in principle. The machine consists of a 
series of coils of wire, which offe a known resistance to the 
electric current. Enough of tho coils are connected to make 
a resistance equal to the resistance offered by the entire cable 
" when it is in working order, and thus, when the machine and 
the cable are connected, a balance is effected. But, if the 
cable should break, the balance is destroyed, because that 
portion of the cable between the shore station and the break, 
wherever it may be, will offer less resistance to the electric 
current than the entire cable would do. Enough coils of wire 
are therefore disconnected from the machine to restore the 
balance. The resistance of the part of the cable that 
remains intact is thus accurately determined by the number 
of coils remaining connected with the machine. Having, 
when the cable w^as intact, learned the resistance which a 
mile of the cable offers, by dividing the entire resistance by 
the number of miles of cable, it is easy to find how many 
miles of cable are still in good order, by dividing the entire 
resistance of the piece by the known resistance of one mile 

Having determined how many miles from the shore 
station the break is, orders are sent to go to the place, pick up 
the ends, and splice them to new piece. Having received such 
an order and acted on it, Captain Trott found himself and 
his ship, on July 25th last, in latitude 42^ 30' north, and 
longitude 46° 30' west, or just to the eastward of the Grand 
Banks ''of Newfoundland, with one of the hardest jobs 
before him that he h^^ ^ad in some time, for sounding 



279 

showed that the wate*- was about 13,000 feet, or a good deal 
more than two miles deep. He knew he was somewhere 
aear the break in the cable, but he did not know absolutely 
within about three or four miles, because, while he had been 
able to determine his own position by repeated observations 
of the sun and stars, he could not tell how accurate the 
observations of the officers of the ship laying the cable had 
been. 

The first work done was to get a series of soundings over 
a patch of the sea aggregating twenty-five or thirty square 
miles. The sounding apparatus consisted of an oblong shot 
of iron, weighing about thirty-two pounds, attached to a 
pianoforte wire in such a way that, when lowered to the bottom^ 
the shot would jab a small steel tube into the mud down 
there, and would then release itself from the wire, and allow 
the sailors to draw up the tube with the mud in it. The 
moment the weight was released, the men on deck stopped 
paying out the wire, and thus, knowing how much wire had 
been run out, they were able to tell the depth. It is a fact 
that it took twenty-four minutes and ten seconds for the 
weight of the oounding apparatus to reach bottom in 2,097 
fathoms of water. 

The ship was now ready to begin the search proper for 
the cabl?. She was run off at right angles to the line of the 
cable for n distance of five miles, and a buoy got down to 
mark the limits of thi> territory to be grappled over in that 
direction. Buoy 3 were afterward r:et elsewhere to mark the 
other limits of the territory. The grappling iron was low- 
ered over :he bows, the rope attached to it passing over one 
of the three big grooved wheels that revolve where the bow- 
sprit of an ordinary vessel stands. 

The grappling iron used is the invention of Captain Trott. 
It looks something like a four-pronged anchor. It has a shaft 
four feet long, and four arms about a foot long, that are set 
at right angles to each other at the bottom of the shaft. 
Right in each crotch formed by the arms is a little button 
that has a spring behind it that may be regulated in strength. 
The button projects a third of an inch into the crotch. The 
angle of the arms with the shaft is so small that a rock could 
not get down in so far as to reach the button ; but, when the 
cable is caught by the hooks, it presses down against the but- 
ton, and thus closes an electrical circuit through a copper 
wire running through the grapnel's rope and the grapnel 
itself, and a bell is set ringing upon deck. But the experi- 
enced m' n in charge of the grappling are generally able to 
telJ wha i: the hook has hold of without the aid of the bell. 



They judge by the strain on the rope, which is indicated by a 
dynamometer on deck. The ordmary strain on the dyna- 
mometer is from 3 to 3X tons when the grapnel is dragging 
^reely over a smooth bottom as the vessel forges slowly ahead. 
:)metimes a rock catches on the hooks. This frequently 
breaks off an arm, but sometimes it fetches clear, the strain 
indicated by the dynamometer informmg the old sailor man 
m charge wheiner an accident has happened or not. 

It took two hours and twenty minutes to get the grap- 
pling iron from the bow of the ship down to the bottom of the 
sea, 13,000 feet below. The cable used to drag it with is the 
patent wire and hemp invention of the captain. The drag- 
ging began on July 25th, the day of arrival, but they swept 
backward and forward over the territory for ten days without 
finding the broken telegraph cable. A good part of the time 
they were steaming back and forth day and night, and the 
only time when they were not doing so was when the weather 
was too bad. On such occasions they went to the buoy at 
the supposed end of the broken cable, and hove to till the 
gale was ended. 

Finally, on August 5th, the bell rang, indicating that the 
grs-pnel had caught the cable. The grapnel drag rope was 
tnereupon fastened to a buoy and thrown overboard. Then 
the steamer went off two miles toward the end of the broken 
cable and got out a cutting grapnel. This is like the other 
one, except that there are knives in the crotches. When 
these crotches catch the cable and strain comes on them, th^ ' 
cut the cable off clean. 

" Why did you cut off the cable there? " was asked. 

" Because, if we had tried to get up the bight of the cable 
where we first found it, the cable might have broken under 
the strain. That cable was laid in 1869, and is getting 
pretty well along in years. It would have been as apt to 
break on the shore side as the other, but, when we had only 
an end of two miles to deal with, we were sure of being abk» 
to get up without damage. We grappled European end first." 

Having cut off the cable, the vessel returned to the buoy 
on the grappling rope, and, getting the rope inboard again, 
led it to £. drum six feet in diameter located on the uppei 
deck andr^^ '^ated by a steam engine. Then they began to 
wind in the grapnel rope and hoist the old cable to the bows. 
They started the drum at i :2o in the afternoon of August 5, 
and at 7:51 had the bight of it at the bow of the ship. Then 
the two miles and odd of end that was hanging down from 
the bow was fished up and stretched in lengths along the 
deck until the end was reached iliis was connected with » 



•/8l 

very complete cable telegraph office located amidships, and 
a second later the operators who had been on watch for days 
in the British station awaiting this event saw the flashes on a 
mirror in their ffice that told them all about it. 

Sometimes it happens that, when an end of the cable is 
picked up in this way, and an attempt is made to communi- 
cate with the shore, it is found that there is another break, 
and that they have only the end of an odd section lying 
loose. Then they have to drop that over, after testing it to 
see how long it is, and go on toward the shore and begin over 
again. In this case, however, they found that they had hold 
of a sound wire to Great Britain. Without any delay, the 
end of a new cable was spliced to the old end brought from 
the bottom. Two experts, one who is trained in splicing 
cores, and one who is trained in spHcing the outside or 
sheathing, are employed in this work. 

When the splice was completed and tested, and found 
perfect, the cable was started, running out around drums 
and grooved wheels controlled by brakes, and over the stern, 
the Old end having been led fair through these sheaves before 
the splicing was done. Then the ship headed for shoal water, 
and ran away at from three to four knots an hour until over 
a part of the banks where w^ork could be done more easily 
than where the water was more than two miles deep. Of 
course this involved the abandonment of a good many miles 
of old cable, but the old cable wasn't of very much impor- 
tance anyliow. 

Arrivmg in shoal water, the end of the new piece was 
attached to a buoy and put overboard. Then the old cable 
was grappled and cut as before, and a new piece spliced to 
it. Then the ends of the two new pieces were spliced to- 
gether and the job was complete. It had taken nearly two 
months to do it, although in the meantime two easier jobs 
were attended to, and a trip to Halifax for provisions was 
made, not to mention the encountering of the storm that 
damaged the rudder. 

The " Minia " has a crew of ninety, all told, including the 
explain, three deck officers, a navigator, three expert elec- 
Inciar.s, four engineers, a purser and a surgeon. A. black* 
smitti and a boiler maker, with their tools, are carried. There 
are three big, round tanks to hold the 600 miles of cable 
cariied, which includes sizes to fit all the old cables under the 
charge of this ship. - There is a cell-room where the electricity 
ibr telegraphing is generated, and two dynamos with their 
engines, one to furnish electricity for a system of arc lights 
used when at work at night, and the other for the incande** 



282. 

cent system that lights the ship below decks. The main 
saloon is large, and is comfortably and handsomely fitted. 
The captain has a cabin under the turtle-back aft, as fine as 
any captain could wish for, and the other officers have rooms 
below that are as well fitted as those usually occupied by 
naval officers. The crew are all expert men, and get pay 
that averages a good deal better than the pay in the packet 
service between New York and Liverpool. The entire crew 
is kept under pay the year round, the ship making her head- 
quarters at Halifax when not engaged in repairing cables. 
They are as comfortable a lot of sailor men as one could find 
anywhere. 

THE USELESSNESS OF LIGHTNING RODS. 

The uselessness of the lightning rod is becoming so 
generally understood that the agents find their vocation a 
a trying one. Fewer and fewer rods are manufactured each 
year, and the day will come when a lightning rod on a 
house will be regarded in the same light as a horseshoe over 
a man's door. 



The breaking strain on various metals is shown in the 
following table, the size of the rod tested being in each case 
one inch square, and the number of pounds the actual break- 
ing strain ; 

Pounds. 

Hard Steel 150,000 

Soft Steel 120,000 

Best Swedish iron 84,000 

Ordinary bar iron 70,000 

Silver. 41,000 

Copper 35^000 

Gold 22,000 

Tin 5.500 

Zinc 2,600 

Lead 860 

To make varnish adhere to metal, add five-hundredths per 
cent, of boracic acid to the varnish. 

Machinery will do almost anything, and what machinery 
can't do a woman can with a hairpin. 

To find the weight of a cast-iron ball, Haswellsays — Mul« 
tiply the cube of the diameter in inches by 1365, and tha 
orodu t is the weight i)i pounds. 



283 

NUMBER OF REVOLUTIONS OF WATCH 

WHEELS. 

Very few who carry a watch ever think of the unceasing 

labor it performs under what would be considered shabby 

treatment for any other machinery. There are many who 

think a watch ought to run for years without cleaning, or a 
drop of oil. Read this and judge for yourself: The main 
wheel in an ordinary American watch makes 4 revolutions 
a day of 24 hours, or 1,460 in a year. Next, the center 
wheel, 24 revolutions in a day, or 8,760 in a year. The 
third wheel 192 in a day, or 59,080 in a year. The fourth 
wheel, 2,440 in a day, or 545,600 in a year. The fifth, or 
'scape wheel, 12,960 in a day, or 4, 728,200 in a year. The 
ticks or beats are 388,800 in a day, or 141,882,000 in a year. 

A VALUABLE POINT FOR HOLDERS. 

It is claimed that a saving, as well as a better job, can be 
effected by the substitution of the following for the coal dust 
and charcoal used with green sand : Take one part common 
tar, and mix with 20 parts of green sand ; use the same as 
ordinary facing. The castings are smooth and bright, as tar 
prevents metal from adhering lo the sand, prevents formation 
of blisters, and helps tlie production of large castings by 
absorbing the humidity of the sand. 

METRICAL EQUIVALENTS. 
As in much of the scientific literature of the. steam engine 
the metrical system of weights and measures is used, 
we publish the following equivalents, which may be of use 
to our readers in readily reducing them to British units: 

1 kilogrammetre 7,23^ foot pounds. 

I foot pound 188 kilogrammetre. 

I French horse power (chevelvapeur) 75 kilo- 
gramme tres per second 9863 horse power. 

I British horse power 1.0139 chevaux. 

I kilogramme per cheval 2,239 pounds H. P. 

I pound per horse power. 447 kilo, per cheval. 

1 caloric, or French heat unit 3968 British units. 

I British thermal unit 252 caloric. 

French mechanical equivalent, 423.55 (usually 

called 424) kilogrammetres 3063. 5 ft. pounds. 

English mechanical equivalent, 772 footpounds 10.76 kilogrammetres. 



A NEW ALLOY. 

An alloy, the electrical resistance of -which diminishes 
with increase of temperature, has recently been discovered. 
It is composed of copper, manganese and nickel. Another 
alloy, due to the same investigator, the resistance of which is 
practically independent of the temperature, consists of 70 
parts of copper combined with 30 of ferro-manganese 

USE OF NATURAL GAS IN CUPOLAS. 

At Pittsburgh, Pa., natural gas has been utilized in 
cupolas for ordinary castings. The apparatus consists of a 
series of pipes, covered with fire-clay tiles, and, at the same 
time, ventilating the pipes with a current of air. A combus- 
tion chamber is necessarily connected with the furnace, to 
insure the required heat and prevent the chilling of the fur- 
nace. 

A NEW CEMENT. 

A cement called magnesium oxychloride, or white cement, 
has been discovered, and is now manufactured in California, 
as we learn from an exchange. It is composed of one-half 
(}4) magnesium oxide, which is obtained from the magnesite 
deposits in the Coast Range, and one-half (J4) magnesium 
chloride, obtained from various sea-salt manufactories 
uiioughout the State. It may be used for sidewalks, and for 
intexior decorating, and in appearance resembles pure white 
marble. It has a natural polish, and, above all, is much 
cheaper than any of the other substances now in use. 

KOW TO CAST A FACE. 

The person whose face is to be "taken" is ])!aced flat 
upon his back, his hair smoothed back by pomatum to pre- 
vent it covering any part of the face, and a conical piece of 
paper or a straw, or a quill put in each nostril to breathe 
through. The eyes and mouth are then closed and the entire 
face completely and carefully covered with salad oil. 'Ihe 
plaster, mixed to the proper consistency, is then poured in 
large spoonfuls to the thickness of one-quarter or one-hair 
inch. In a few minutes this can be taken off as if it were a 
film. When a cast of the entire head or of the whole human 
figure is required, either a cast of the face is added to a mass 
of clay, which is to be modeled to the required figure, or the 
whole figure is modeled from drawings prepared for th-'' 
purpose Tl::s is the work of the sculntor- 



285 

When the clay model is finished, a mold is made from it 
as in the former cases. If the model be a bust, a thin ridge 
of clay is laid along the figure from the head to the base, and 
the front is first completed up to the ridge by filling up the 
depressions two or three inches deep. The ridge of clay is 
now removed, the edges of the plaster are o'^led, and the 
other half is done in a similar way. The tw^d htilves are like- 
wise tied together with cords, and the plaster is poured in. 
In complicated figures, say a " Laoccon," the statue is oiled 
and covered with gelatine, which is cut off in section?: by 
means of a thin, sharp knife, each piece serving as a iviold 
for its own part of the new statue. 

' MELTING POINTS OF METALS. 



Metals. 



Aluminum. . . . 
Antimony . . . 

Arsenic , 

Bismuth . . . . , 
Cadmium .... 

Cobalt 

Copper 

Gold 

Indium 

Iron, wrought 
Iron, cast . . . . 
Iron, steel . . . 

Lead 

Magnesium. . . 

Mercury 

Nickel 

Potassium. . . . 
Platinum .... 

Silver 

Sodium , 

Tin.. , 

Zinc 



Centigrade. 


Fahrenheit. 


degrees 


700 


degrees 


1,292 




425 


(( 


797 


66 


i«5 


a 


365 


a 


264 


it 


507.2 


a 


320 


« 


608 


ti 


i,200 


(C 


2,192 


6i 


1,091 


(( 


1,995.8 


<e 


1,381 


a 


2,485.0 


<( 


176 


C( 


348.8 


ce 


i»530 


ti 


2,786 


«< 


1,200 


<< 


2,192 


(C 


1,400 


(« 


2,552 


<( 


334 


ce 


617 


(C 


235 


<( 


455 


ii 


— 40 


(S 


—40 


(( 


1,600 


(( 


2,912 


(( 


62 


(( 


143.6 


<( 


2,600 


a 


4,712 


<( 


1,040 


(( 


1,904 


<e 


96 


}( 


172.8 


cc 


235 


(( 


455^ 


(( 


412 


a 


773-6 



THE HIGHEST RAILROAD IN THE UNITED 

STATES. 
The highest railroad in the United States is the Denver 
& Rio Grande, Marshall Pass, 10,853 feet. 



286 



WEIGHT AND SPECIFIC GRAVITY OF METAL. 



Metals. 



Aluminum. . 

Antimony, cast 

Bismuth 

Brass, cast . . • . 

Bronze 

Copper, cast. . . 

' ' wire . . . 

Gold, 24 carat . 

** standard. 

Gun -metal 

Iron, cast 

" wrought. . 
Lead, cast 

'' rolled . . . 

Mercury 

Platinum 

*' sheet.. 
Silver, pure. . . . 

*' standard 

Steel. 

Tin, cast 

Zinc 



Wt. pr 
cubic ft. 



Lbs. 
166 
419 
613 
524 
534 
537 
555 
1208 
1 106 
528 

450 
485 
708 
711 
849 
1344 
1436 
654 
644 
490 
455 
437 



Wt. 



pr 



cubic ft. 



Lbs. 

.096 

.242 

•353 

•3 

.308 

•31 

•32 

.697 

.638 

•304 

.26 

.28 

.408 

.d.i 

.489 

•775 
.828 

'Zll 
•371 
.284 
.262 
.252 



Specific 
grav. 



2.67 
6.72 
9.822 
8.4 
8.561 
8.607 
8.9 

19.361 

17.724 

8.459 

7.21 

7.78 

11.36 
II. 41 
i3^596 
21.531 

23- ^ 

10.474 

10.^12 

7^85 
7.29 

7- 



HOW TO MEND PATTERNS. 

For mending patterns needing temporary repairs,or for 
making additions where but one or two molds are to be 
made, the following material will be found very useful. 
Melt together i pound beeswax, i pound rosin and one 
pound parafhne wax. It is well to note here that the bees- 
wax intended is the wax made by the bees, and not the 
wax made by the wholesale dealers. The cheap wax sold 
to the shipping houses contains but a small portion of 
the article made by the bees, and a large proportion of 
soft paraffine wax. The result of using this compound wax 
instead of the genuine article, in any mixture, is to intro- 
duce too much paraffine and only a little beeswax. When 
the genuine article is used, this mixture will be found 
very useful for making addition to patterns, temporary 
patterns, and for a variety of purposes in pattern shop. 



28; 

VALUE OF METALX 
Gold by the pound avoirdupois. 

Vanadium (cryst. fused) $4,792.40 

Rubidium (wire) 3,261.60 

Calcium (electrolyctic) 2,446.20 

Tantalum (pure) , 2,446.20 

Ceriaim (fused globules) 2,446.20 

Eithium (globules) 2,228.79 

Lithium (wire) 2,935.44 

Lubium (fused) 1,671.57 

Didymium (fused) i ,620.08 

Strontium (electrolyctic) o. 1,576.44 

Indium (pure) 1,522.08 

Ruthenium 1,304.64 

Columbium (fused) 1,250.28 

Rhodium 1,032.84 

parium (electrolyctic) o 924. 12 

Fallium 73^-39 

Osmium „ , 652.32 

Palladium 498.30 

Iridium -> 466. 59 

Uranium 434.88 

Gold 299.72 

Titanium (fused) 239.80 

Tellurium " 196.20 

Chromium " 196.20 

Platinum " 122.31 

Manganese " 108. 72 

Molydenum. 54. 34 

Magnesium (wire and tube) 45-30 

Potassium (globules) 22.65 

Silver 18.60 

Aluminum (bar) 16.30 

Cobalt (cubes) [ 12.68 

Nickel 3.80 

Cadmium , 5.26 

Sodium 3.26 

Bismuth (crude) 1.95 

Mercury. 1. 00 

Antimony .36 

Tin... .25 

Copper .22 

Arsenic , o.,,. .15 

Zinc , , .. .10 

Lead .06 

Irom. ^ .13^ 



288 

LENGTH PER COIL AND WEIGHT OF ROPE PER 
HUNDRED FATHOMS. 











Tarred 




Manila and Sisal R 


ope. 


1 


C( 
Le'gth 


Drdage. 


Diameter in 


Cir. in 


Le'gth 


Lbs. 


Lbs. 


inches. 


inches 


in feet. 


per 
100 Fa 


in feet. 


per 

100 Fa 


X or 6th. 


% 


1,300 


12 


840 


18 


5-16 or 9th. 


15-16 


1,300 


17 


840 


29 


Ys or I2th. 


iy% 


1,200 


23 


840 


40 


15 thread. 


15 thread. 


1,200 


31 


840 


47 


18 thread. 


18 thread. 


1,100 


45 


840 


^^8 



21 thread. 


21 thread. 


1,100 


50 


840 


68 


y^ . 


iK 


990 


52 


960 


64 


9-16 


iYa, 


990 


70 


960 


79 


'6 


2 


990 


83 


960 


94 


u 


2^ 


990 


105 


960 


130 


% 


2K 


990 


125 


960 


140 


15-16 


2I4: 


990 


155 


960 


170 


I 


3 , 


990 


175 


960 


207 


1 1-16 


3^ 


990 


205 


960 


238 


1 3-16 


3>^ 


990 


255 


960 


272 


iX 


3l< 


990 


280 


960 


300 


1 5-16 


4 , 


960 


310 


960 


332 


in 


4^ 


960 


355 


960 


31^ 


1% 


aVz 


960 


410 


960 


440 


iVs ^ 


aU 


960 


450 


960 


505 


I 11-16 


5 , 


960 


500 


960 


573 


lU 


5^ 


960 


550 


960 


610 


1% 


sK 


960 


610 


960 


654 


I 15-16 


SI4: 


960 


690 


960 


797 


2 


6 


960 


750 


960 


900 


2 3-16 


6>^ 


960 


845 


960 


1.057 


2% 


7 , 


960 


1,000 


960 


1,163 


2% 


1/2 


960 


1,100 


960 


1.356 


2% 


8 


960 


1,270 


960 


1,613 


3 


9 


960 


1^595 


960 


2,013 



HOW TO MAKE BRONZE MALLEABLE. 

Domier has discovered that bronze is, rendered malleable 
by adding to it from one-half to two per cent, of mercury 



2,Sg 

WHEN A DAY'S WORK BEGINS. 

The decision of the Supreme Court that a workman who 
has agreed to do work at a specified sum per hour, is not 
entitled to charge for the time spent in gomg to or returning 
trom work, is one that equitably applies to some kinds of 
business, but not to others. Where house-building mechan- 
ics have several days' work to do at a building, and their 
tools and materials are on the spot, they are expected to re- 
port at the building in time to do a full day's work. Where 
they are doing odd jobs and are obliged to start from the 
shop in the morning, they do so at the regular hoar for 
beginning work, thus reducing the hours of actual labor 
But they must be paid for the whole day, and the person for 
whom the vvork is done must be charged for the time occu- 
pied in going to and from the job; otherwise, the " boss" 
A'ould have to pay his journeymen, for say ten hoiu-s' work, 
though accounting for only six hours work' in his bill to cus- 
tomers. In some of the small trades a journeyman will go to 
half a dozen houses in a day, doing an hour's wo^k in each, 
and spending the other four hours in passing from one job to 
another. In one way cr another he is bound to be paid for 
the whole time. If he can charge only for the actual work- 
ing time, then his rates will be increased so as to compensate 
him for the time spent in service that is not to be paid for. 
The decision shows the importance of making agreements of 
this kind specific, both as to the rate of wages and the hours 
and kmd of service. 

CAMEL'S-HAIR BELTING. 

Camel' s-hair belting has been recently the subject of 
experiments at the Polytechnic school, at Mul\ ?ch, from 
which it aopears that the strength of camel's-hair belting 
reaches 6,315 pounds per square mch, whilst that of ordinary 
belting ranges between 2,230 pounds and 5,260 pounds per 
square inch. A contemporary says the camel's-hair belt is 
said to work smoothly and well, and it is unaffected by 
acids, 

TO PERFORATE GLASS. 

In drilling glass, stick a piece of stiff clay or putty on tlie 
part where you wish to make the hole. Make a hole in the 
putty the size you want the hole, reaching to the glass, of 
course. Into this hole pour a little molten lead, when, 
unless it is very thick glass, the piece will immediately drop 
out. 



290 

HIGH SPEED GEARING. 

During the last few years, and particularly since the 
adoption of double-heliacal teeth, a great increase has been 
made in speed at which gearing is run, and, in many cases, 
there are now successfully adopted speeds which in former 
days would have been regarded as utterly impracticable. 
The most striking instances of this which we have come 
across, is in the case of a pair of double-heliacal wheels at 
the works of Messrs. R. Johnson & Nephew, the well-known 
wire-drawers of Manchester. These wheels, which were cast 
by Messrs. Sharpies & Co., of Ramsbottom, Lancashire, are 
12 in. wide on the face, by 6 ft. 3 in. diameter, and they have 
now been running for over a year at 220 revolutions per 
minute, the pitch-line speed being thus 4,319 ft. per minute. 
Notwithstanding this enormous speed, the wheels run with 
scarcely ^ny noise, and their working has been most satis- 
factory. This is the highest speed we have heard of for 
geared wheels, running iron to iron, and the fact that it haa 
been adopted with success, is a most interesting one. 

The large gear on the Corliss engine at the Centennial 
Exhibition was 30 feet in diameter, outside, and run at 36 
revolutions per minute. It had a 24-in. face, and the speed 
of the pitch-line is about 3,360 ft. per minute. This speed is 
exceeded by a similar gear, also made by Mr. Corliss, which 
is now running in a mill in Massachusetts. It is 30 ft. in 
outside diameter, and has a 30-in. face. It makes 50 revolu- 
tions per minute, and the speed of the pitch-line is not far 
from .4,670 ft. per minute. This is probably the highest 
speed at which any gear has yet been run continuously. 

The Corliss gears are all accurately shaped by a revolving 
cutter; but it is probable that Messrs. Sharpies & Co.'s gears 
are not cut, but cast, and then finished up by hand. If that 
is the case, their performance is much more remarkable than 
that of the Corliss gears. 

THE WATCH AS A COMPASS. 
Due south can be readily ascertained if one possesses a 
fairly correct watch and the position of the sun is distin- 
guishable. Point the hour hand to the sun, and the south is 
exactly half-way between the hour and the figure XII on 
the watch. For instance suppose that it is 4 o'clock. Point 
the hand indicating IV to the sun and II on the watch is 
exactly south. Suppose that it is 8 o'clock, point the hand 
indicating VIII to the sun, and the figure X on the watch 
is due south. 



^9* 

LIABLE TO SPONTANEOUS COMBUSTION. 

Cotton-seed oil will take fire even when mixed with 
cwenty-five per cent, of petroleum oil ; but ten per cent, of 
mineral oil mixed with animal or vegetable oil, will go far to 
prevent combustion. 

Olive oiJ is combustible, and, mixed with rags, hay or 
sawdust, will produce spontaneous combustion. 

Coal dust, flour-dust, starch (especially rye flour), are all 
explosive when with certain proportions of air. 

New starch is highly explosive in its comminuted state, 
also sawdust in a very fine state, when confined in a close 
shute, and water directed on it. Sawdust should never be 
used in oil shops or warehouses to collect drippings or leak- 
ages from cask«. 

Dry vegetable or animal oi4 inevitably takes fire, when 
saturating cotton waste, at 1 80° F. Spontaneous combustion 
occurs most quickly when the cotton is soaked with its own 
weight of oil. The addition of forty per cent, of mineral oil 
(density .890) of great viscosity, and emitting no inflammable 
vapors, even in contact with an ignited body at any point 
below 338° F. , is sufficient to prevent spontaneous combustion, 
and the addition of twenty per cent, of the same mineral oil 
doubles time necessary to produce spontaneous combustion. 

Greasy rags from butter, and greasy ham bags. 

Bituminous coal in large heaps, refuse heaps of pit coal, 
hastened by wet, and especially when pyrites are present in 
the coal ; the larger the heaps the more liable. 

Timber dried by steam pipes or hot water, or hot air 
heating apparatus, owing to fine iron dust being thrown off, 
in close wood-casings, or boxings round the pipes, from the 
mere expansion and contraction of the pipes. 

Patent dryers from leakages into sawdust, etc., ©ily waste 
of any kind, or waste cloths of silk or cotton, saturated with 
oil, varnish, turpentine. 

HOW COMBUSTION IN COAL IS PFODUCED. 

In a ton of anthracite coal, there is about 1,830 lbs. of car- 
bon, 70 lbs. of hydrogen and 52 lbs. of oxygen; while a toa 
of good bituminous coal is composed of 1,600 lbs. of carbon, 
108 lbs. of hydrogen and 32 lbs. of oxygen. The combus- 
tion of coal proceeds from its combination with oxygen gas, 
and, when fuel of any kind combines with oxygen, heat is pro- 
duced. All bodies, substances, gases and liquids, are com- 
posed of separate particles, often of molecules of inconceiv- 
•^ble sma.llness. These particles, it is scientifically conceded. 



292 

are m motion among themselves, and this motion constitutes 
heat, for heat is only a kind of motion. This internal vibra- 
tion of infinitesimal particles may be transmuted into a per- 
ceptible mechanical movement, or the mechanical movement 
may be converted into the invisible motion called heat. The 
oxygen combined with coal has a very considerable range of 
internal motion, and the combining process produces carbonic 
acid gas; and, the particles of this gas having a much smaller 
range of motion than the particles of the oxygen have, the 
difference appears in the form of heat. " 

CAPACITY OF CYLINDRICAL CISTERNS. 

The following table shows the capacity in gallons for 
each foot in depth of cylindrical cisterns of any diameter: 
Diameter. Gallons. Diameter. Gallons. 



25 ft. 


3.059 


7 ft. 


239 


20 ft. 


1,958 


6/2 ft. 


206 


15 ft. 


I,IOI 


6 ft. 


176 


14 ft. 


959 


5 ft. 


122 


13 ft. 


827 


4Kft. 


99 


12 ft. 


705 


4 ft. 


78 


II ft. 




3 ft. 


44 


10 ft. 


489 


2>^ft. 


30 


9 ft. 


396 


2 ft. 


19 


8 ft. 


313 







HOW TO SELECT A HAND SAW. 

A saw-maker has this advice to give to carpenters In the 
selection of a saw: 

"See that it 'hangs' right. Grasp it by the handle and hold 
it in position for working to see if the handle fits the hand 
properly. A handle should be symmetrical, and the lines 
perfect. Many handles are made of the green wood; they 
soon shrink and become loose, the screws standing above 
the wood. An unseasoned handle is liable to warp and throw 
the saw out of shape. Try the blade by springing it, seeing 
that it bends evenly from point to butt in proportion as the 
width and gauge of the sav/ vary. The bl'ide should not be 
too heavy in comparison to the teeth, Jis it will require more 
labor to iise it. The thinner you can get a stiff saw the bet- 
ter; it makes less "kerf and takes less muscle to drive it. 

*'See that the saw is well set and has a good crowning 
breast. Place it at a distance from you; .^et a proper light 
on it, and you can see if there has been any imperfections in 
grinding or hammering." 



293 

FROM ONE TON OF COAL. 

Prom one ton of ordinary gas coal may be produced 1,500 
pounds of coke. 20 gallons of ammonia water and 140 pounds 
of coal tar. By destructive distillation the coal tar will 
yield 69.5 pounds of pitch, 17 pounds of creosote, 14 pounds 
of heavy oils, 9.5 pounds of naphtha yellow, 6.3 pounds of 
naphthaline. 4.75 pounds of naphthol, 2.25 pounds of solvent 
naphtha, 1.5 pounds of phenol, 1.2 pounds of aurine, 1.1 
pounds of benzine, 1.1 pounds of analine, 0.77 of a pound of 
toludine, 0.46 of a pound of anthracine and 0.9 of a pound of 
toulene. From the latter is obtained the new substance 
known as saccharine, which is 530 times as sweet as the best 
cane sugar, one part of it giving a very sweet taste to a thou- 
sand parts of water. 

HOW TO SELECT ROPE. 

A German paper, in an article on the present methods of 
rope manufacture from hemp, and the determination of the 
different qualities and the probable strength simply from the 
appearance, lays down the following rules : A good hemp 
rope is hard but pliant, yellowish and greenish gray in color, 
with a certain silvery or pearly luster. A dark or blackish 
color indicates that the hemp has suffered from fermentation 
in the process of curing, and brown spots show that the rope 
was spun while the fibers were damp, and is consequently 
weak and soft in those places. Again, sometimes a rope is 
made with inferior hemp on the inside, covered with yarns 
of good material — a fraud, however, which may be detected 
by dissecting a portion of the rope, or, in practical hands, by 
its behavior in use ; other inferior ropes are made with short 
fibers, or with strands of unequal strength or unevenly spun 
— the rope in the first case appearing wooly, on account of 
the number of ends of fil.)er projecting, and, in the latter 
case, the irregularity of manufacture is evident on inspection 
by any good judge. 

THINGS THAT WILL NEVER BE SETTLED. 

Whether a long screw-driver is better than a short one 
of the same family. 

Whether water-wheels run faster at night than they do in 
the day time. 

The best way to harden steel. 

Which side of the l)elt should run next to the pulley. 

The proper speed of line shafts. 

The right way to lace belts. 

Whether cojupression is economical or the reverse. 

Th'^ ])rincip!e of the sleara injectoi-. 



294 
THINGS WORTH KNOWING. 

Dominer has discovered that bronze is rendered malleable 
by adding to it from one-half to two per cent, of mercury. 

An " inch of rain " means a gallon of water spread over a 
surface of nearly two square feet, or a fall of about loo tons 
on an acre of ground. 

A steam power plant is divided into five fundamental 
■parts by a French author — the boiler, motor, condenser, 
distributing mechanism, and mechanism of transmission. 

Turpentine and black varnish, put with any good stove 
polish, is the blackening used by hardware dealers for polish- 
ing heating stoves. If properly put on, it will last throughout 
the season. 

A workman in the Carson mint has discovered that drill 
points, heated to a cherry-red and tempered by being driven 
into a bar of lead, will bore through the hardest steel or plate 
glass without perceptibly blunting. 

To harden copper, melt together, and stir till thoroughly 
incorporated, copper and from one to six per cent, of mand- 
ganese oxide. The other ingredients for bronze and other 
alloys may then be added. The copper becomes homogene- 
ous, harder and tougher. 

SIMPLE TESTS FOR WATER. 

Boiler-users who desire simple tests for the water they 
are using will find the following compilation of tests both 
useful and valuable : 

Test for Hard or Soft ^<a;^^r— Dissolve a small piece 
of good soap in alcohol. Let a few drops of the solution 
fall into a glass of the water. If it turns milky, it is hard 
water ; if it remains clear, it is soft water. 

Test for Earthy Matters or Alkali — Take litmus-paper 
dipped in vinegar, and, if on immersion the paper returns 
to its true shade, the water does not contain earthy matter 
or alkali. If a few drops of syrup be added to a water con- 
taining an earthy matter, it will turn green. 

Test for Carbonic Acid— Take equal parts of water 
and clear lime water. If combined or free carbonic acid is 
present, a precipitate is seen, to which, if a few drops of 
muriatic acid be added, effervescence commences. 

Test for Magnesia — Boil the water to twentieth part of 
its weight, and then drop a few grains of neutral carbonate 
of ammonia into a glass of it and a few drops of phosphate 
of soda. If magnesia is present, it will fall to the bottom. 



^95 

Test fo7- Iron— BoW a little nut-gall and add to the 
water. If it turns gray or slate-black, iron is present. 
Second: Dissolve a little prussiate of potash, and, if iron ii 
present, it will turn blue. 

Test for Lime — Into a glass of water put two drops of 
oxalic acid, and blow upon it. If it gets milky, lime is present 

Test for Acid — Take a piece of litmus-paper If it 
turns red, there must be acic[. If it precipitates on adding 
lime water, it is carbonic acid. If a blue sugar paper is 
turned red, it is a mineral acid. 

Test for Copper — If present, it will turn bright 
polished steel a copper color. Second : A few drops of 
ammonia will turn it blue, if copper is present. 

Tests for Lead — Take sulphureted gas and water in 
equal quantity to be tested. If it contains lead, it will turn 
a blackish brown. Again : The same result will take place 
if sulphate of ammonia be used. 

Test for StdpJuir — In a bottle of water add a little 
q ksilver, cork it for six hours, and, if it looks dark on 
th Dp, and on shaking looks blackish, it proves the presence 
of sulphur. 

JAPANESE LACQUER FOR IRON SHIPS. 

The Japanese Admiralty has finally decided upon coating 
the bottoms of all their ships with a material closely akin to 
the lacquer to which we are so much accustomed as a 
specialty of Japanese furniture work. Although the prep- 
aration differs somewhat from that commonly known as 
Japanese lacquer, the base of it is the same — viz., gum-lac, 
as it is commonly termed. Experiments, which have been 
long continued by the Imperial Naval Department, have 
resulted in affording proof that the new coating material 
remains fully efficient for three years, and the report on the 
subject demonstrates that, although the first cost of the 
material is three times the amount of that hitherto employed, 
the number of dockings required will be reduced by its use to 
the proportion of one to six. K vessel of the Russian Pacific 
fleet has already been coated with the new preparation, 
which, the authorities say, completely withstands the fouling 
influences so common in tropical waters It took the native 
inventor many years to overcome the tendency of the lac to 
harden and crack; but having successfully accomplished this, 
the finely-polished surface of the mixture resists in an almost 
perfect degree the liabilitv o'^ barnacles to adhere or weeds ^o 



296 

grow, while, presumably, the same high polish must materi- 
ally reduce the skin friction which is so important an element 
affecting the speed of iron ships. The dealers in gum-lac 
express the fear lest the demand likely to follow on this novel 
application of it may rapidly exhaust existing sources of 
supply. 

IRON IN THE CONGO. 

Recently Mr. Dupont, director of the Museum of Natural 
History of Brussels, went to the Congo for the pm'pose of 
studying the geology of the valley from the Atlantic to the 
confluence of the Kassai River, over 400 miles from the coast. 
After eight months devoted to this w^ork, he has returned to 
Europe, bringing some sury^rising reports with regard to the 
mineral resources of the region. He says that throughout 
the entire extent of the country he found in the plateaus 
skirting the river, under the thick alluvium, a stratum of iron 
ore from a foot and a half to three feet in thickness. In 
numerous places he saw blocks of iron ore sometimes many 
cubic feet in dimensions, upon the slopes of ravines, where 
they had been exposed by denudation. He asserts that there 
is scarcely a country in the world so rich in iron ore as the 
Cor.^^o basin, and the mineral is not only abundant, but can 
also be easily reduced. In his opinion, if the other continents 
ever exhaust their resources of iron, the Congo basin can sup- 
ply the rest of the world for a long period. 

GLASS CUTTING BY ELECTRICITY. 

The cutting of glass tubes of wide diameter is another of 
the almost innumerable industrial applications of electricity. 
The tube is surrounded with fine wire, and the extremities of 
the latter are put in communication with a source of electricity, 
and it is of course necessary that the wire adhere closely to 
the g'.ass. When a current is passed through the wire, the 
latter becomes red hot and heats the glass beneath it, and a 
single drop of water deposited on the heated place, will cause 
a clean breakage of the glass at that point. Contrary to 
what takes place with the usual processes in the treatment of 
this frangible material, it is found that, the thicker the sides 
of the tubes are, the better the experiment succeeds. 

Glass, as far as research has been able to determine, 
was in use 2,000 years before the birth of Christ, and was 
even then not in its infancy. 



29/ 

Miil^NESS CAUSED BY THE ELECTRIC 
LIGHT. 

A curious phenomenon was recently related by M. D' Ar 
sonval before the French Academy of Medicine. After gazing 
for a few seconds on an arc light of intense brilliancy, he 
suddenly became deaf, and remained so for nearly an hour 
and a half. Surprised, and somewhat alarmed in the first 
instance, but reassured by the disappearance of the symp- 
toms, he repeated the experiment with the same result. 
When only one eye was exposed to the light, no very marked 
effect was produced. 

BROWNING GUN BARRELS. 

Mix 1 6 parts sweet spirits niter, 12 parts saturated solu- 
tion of sulphate of iron, 12 parts chloride of antimony. Bot- 
tle and cork the' mixture for a day, then add 500 parts of 
water and thoroughly mix. Clean the barrel to a uniform 
grain free from grease and finger stains. Wipe with a stain- 
ing mixture on a wad of cotton. Let it stand for twenty-four 
hours, scratch brush the surface and repeat twice. Rub off 
the last time with leather moistened with olive oil. Let dry 
a day, and rub down with a cloth moistened with oil to 
polish. 

SPONTANEOUS COMBUSTION 

There is a remarkable tendency observable in tissues and 
cotton, when moistened with oil, to become heated when 
oxidation sets in, and sad results often follow when this is neg- 
lected. A wad of cotton used for rubbing a painting has 
been known to take fire when thrown through the air. The 
waste from vulcanized rubber, when thrown in a damp con- 
dition into a pile, takes fire spontaneously. Masses of 
coal stored in a yard have been known to take fire without a 
spark being applied, and one cannot be too careful in 
storing any substance in which oxidation is liable to take 
place. 

A LARGE LUMP OF COAL. 

One of the largest lumps of coal ever mined in the Monon- 
gahe la Valley was taken from J. S. Neels' Cincinnati mines, 
near Monongahela City, lately. The blocic measured 7 feet 
8 inches long, 3 feet 5 inches high, and 3 feet 7 inches wide. 
A temporary track was laid to the river, and the big piece o* 
al loi,ded in a ):)oat for Cincinnati. 



29S 

SCREW-MAKING AT PROVIDENCE, RHODE 
ISLAND. 

It is not known when screw^s were first made and brought 
into use. The first instance known of machinery being applied 
to the making of screws, was in France, in 1569, by a man 
named Besson, who contrived a screw-cutting gauge to be 
used in a lathe. The early method had been to make the heads 
by pinching the blanks while red hot between dies, and then 
to form the threads by the process of filing. In 1 741 Besson's 
device was improved by Hindley, a watchmaker, of York, 

England; and for a long time the watch-makers of that 
country used this device in making the small screws used in 
their work. The first English patent appears to have been 
issued to Job and William Wyatt, in 1760, for three machines 
— one for making blanks, another for nicking the heads, and 
a third for cutting the threads. Between that date and 1840 
about ten patents were issued, only one of which is worthy of 
notice, namely that of Miles Berry, dated January 28, 1837, 
which was for a gimlet-pointed screw. Tlie tirst American 
patent was i.^'^ued December 14, 1798, to David Wilkinson, a 
celebratea mechanic of Rhode Island. The next Americaa 
patent was dated March 23, 1813, and was issued to Jacob 
Perkins, of Newburyport, Mass. In that year, also, a patent 
was granted to Jacob Sloat, of Ramapo, N. Y. At the exten- 
sive nail and iron works of the Piersons, established in Ram- 
apo^ in 1798, Thomas W. Harvey in 1831 applied the tog- 
gle-joint to the headings of screws, rivets and spikes In 1834 
Mr. Harvey entered into partnership with Frederick Goodell, 
a cotton manufacturer of Ramapo, and established a small 
screw manufactory^ at Poughkeepsie, and early in the next 
year^ Mr. Harvey invented machines for heading, nicking and 
shaving screws. ^ These and a thread-cutting machine, pur- 
chased from its inventors, Jacob Sloat and Thomas Spring- 
steen, were successfully operated, producing a gimlet-pointai 
screw. 

It is interesting to note that, while the manufacture oi 
wood screws probably originated in Westphalia, Germany, 
and was subsequently carried on in eastern France and Eng- 
land before its introduction into this country, American in- 
ventors have supplied the machinery that is now universally 
employed. The popular feeling that the gimlet-pointed screw 
was a modern invention is erroneous. The company has in 
hs possession sample cards of French screws, pointed, thou^ii 



299 

not as perfectly made as at present, which Avere brought from 
France early in the present century, and from an old piano 
now at Northampton, made about the year 1750, screws have 
been taken showing the same feature. Patents have been 
issued on gimlet-pointed screws, but they covered only a 
peculiar form of point. 

The Eagle Mill of the American Screw Company is 
devoted to the manufacture of wood screws. In the yard 
connected with this mill are landed the rods, in coils, from 
which the screws are to be manufactured. The larger por- 
tion of these rods is imported from Sweden, Germany and 
England. The first room into which the reader is to be con- 
ducted is the -'pickling room." Here the rod is "pickled" 
for the purpose of removing the flinty scale on the outside; 
and the action of the mixture in that process tends to facil- 
itate the drawing of the wire. After being annealed in fur- 
naces the wire is subjected to the pointing process, the pur- 
pose of which is to reduce the end of the rod to enter the 
draw-plate. The wire is taken into the drawing room, where 
it is drawn in different sizes needed for the great variety of 
screws. The machinery for the different processes is the 
result of the skill of many inventors, who have produced a 
system of machines mostly automatic and beautiful in opera^ 
tion By the automatic wire block used, if anything happens 
to the wire while going through the process, the whole appa- 
ratus stops. If it did not stop, the wire would break. By a 
machine, whose action is accurate and fascinating, the rod 
is cut into the sizes of the screws desired and the head 
put on almost at the same instant. The metal, in going 
through this process, necessarily becomes very oily. 
These " blanks," for such they are called at this stage 
of their manufacture, are put into what are called "rat- 
tlers," revolving boxes, hexagonal in shape, tilled with saw 
CXLS%, where they are cleansed of the oil that covers them, the 
oil peing absorbsed by the sawdust. The blanks are ready to 
tare their heads "shaved," which consists in cutting the 
he^^ds perfectly round. The blanks are put into a hopper, and 
by an automatic feeder they are let down into a trough, from 
which they are picked by a metal finger and put into a spin- 
dle. The heads are then "shaved," and by a revolving spin- 
dle the blank is taken to the small saw which cuts the slot in 
the head. The blank is then revolved back again and shaved 
again, to get rid of the "burr," or the rough edge left by the 
tool, in cutting the slot. The blanks are then fired out of 
tie machine absolutely perfect. The machine is an automatic 



300 

but very complicated one ; every part of it, however, does its 
work effectively. The blanks, after being shaved and slotted, 
are placed in another machine and threaded, when the screw 
is complete. 

HOW THERMOMETERS ARE MADE. 

The first point, in the construction of the mercurial ther- 
mometer, is to see that the tube is of uniform caliber through- 
out its whole interior. To ascertain this, a short column of 
mercury is put into the tube and moved up and down, to see 
if its length remains the same through all parts of the tube, 
If.a tube whose caliber is not uniform is used, slight differ- 
ences are made in its graduation to allow for this. A seals 
of equal parts is etched upon the tube; and from observations 
of the inequalities of the column of mercury moved in it, a 
table giving the temperatures corresponding to these divisions 
is formed. A bulb is now blown on the tube, and while the 
open end of the latter is dipped into mercury, heat is applied 
to the bulb to expand the air in it. This heat is then with- 
drawn, and the air within contracting, a portion of the mercury 
rises in the tube, and partly fills the bulb. To the open end of 
the bulb a funnel containing mercury is fitted, and the bulb 
is placed over a flame until it boils, thus expelling all air and 
moisture from the instrument. On cooUng, the tube 
instantly fills with mercury. The bulb is now placed in 
some hot fluid, causing the mercury within it to expand and 
flow over the top of the tube, and, when this overflow has 
ceased, the open end of the tube is heated with a blow-pipe 
flame. To graduate the instrument, the bulb is placed in 
meltmg ice; and, when the top of the mercury column has 
fallen as low as it Avill, note is taken of its position as com- 
pared with the scale on the tube. This is the freezing point. 
It is marked as zero on the thermometers of Celsius and 
Reaumur, and as 32^ on the Fahrenheit class. 

To determine the boiling point, the instrument is placed 
in a metallic vessel with double walls, between which circulates 
the steam from boiling water. Between the freezing and 
boiling point of water, 100 equal degrees are marked in the 
centigrade graduation of Celsius, t8o° on the Fahrenheit 
plan, and 80^ on the Reaumur. In many thermometers, all 
three of these graduations are indicated on the frame to which 
the tube is attached. Some weeks after a thermometer has 
been made and regulated, it may be noticed that, when the 
bulb is immersed in pounded ice, the mercury does not quite 
descend to the freezing point This is owing to a gradual 
expansion of the mercury, whicn usually goes on for nearly 



30I 

cwo years, when it is found that the zero point has risen 
uearly a whole degree. It is then necessary to sUde down 
tne scale to which the tube is fastened, so that it will accurately 
read the movements of the mercury. After this change, the 
accuracy of the thermometer is assured, as there is no further 
«cpansion of the mercury column. 

POINTS FOR APPRENTICES. 

In starting to learn a trade as an apprentice, first imagine 

yourself brighter, and more apt to learn, than the older 

apprentices in the shop. Criticise their work on the last range 
they blacked. Show the red spots under the doors or under 
the top plates, and if you are not dropped through the trap 
door into the cellar the first opportunity they get, it will be 
some good fortune that favors you. When working with a 
jour., tell him how Tom Jones does that, and his ways are 
aot right, or tell him how to do it. Of course the jour, has 
worked fifteen years at the business, but that doesn't make 
any difference, you go ahead. If he does not call you cuss 
words and tell you to mind your business, he must have 
a mother-in-law who comes over to see him seven times a dayi 
and stays all day Sunday. 

When you have worked about a year at the business, and 
you think you are competent to take charge of the shop, and 
you are given a job of cleaning a furnace, which, of course, 
will smut a boiled shirt, you go home, and kick to the old 
folks; say you are not going to work for Smith any more, as 
he gives you all the dirty work to do, and get the old folks to 
go around and see Smith about their precious boy. It will 
make you, in the eyes of Smith, as large as Jumbo to a rat. 

When you worry your term of apprenticeship through 
and you receive the title of jour., of course you demand jour.'s 
wages, say as much as old man Stewpot. He has worked 
eighteen years m the stiop, but that doesn't matter. Why, 
you made six dozen joints of stove pipe in two hours and it 
took himthree.* Well, if you don't make satisfactory arrange- 
ments, I heard Billy Doepan say that Enos Kettle, at Inkville, 
wanted a man, and you, of course, strike; it pays bio; wages to 
T'. first-class man. You go and see Kettle and he asks you 
what you can do. Of course you worked on the cornice for the 
Grand Opera House, and on the button factory, and several 
other jobs too numerous to mention. You receive a position 
to help Kettle out on the Green buildin^r cornice. This being 
Thursday night, and he has to go to Plumtown to finish up a 
job, he would like to have you come on iii the morninij. He 



302 

gives you a simple piece of cutting to keep you going until hb 
return on Saturday night, when he makes a practice of paying, 
off his help. You come under this head, and find that he offers 
you the enormous sum of seventy-five cents per day, and orders 
the stove porter to go and cover the pig trough with your two 
days' work to keep the pigs from making post holes in their 
trough, which his wife vv^anted him to do for the past nine 
months. You declare he is a crank; you are going West, or 
to some seaport town. 

You strike out and get a position in a roofing shop paint- 
ing tin. You write home to 3^our brother chip telling what 
a position you have, what big wages, etc. , but not giving 
original facts. In a few years you return home broken 
down, with no trade. You can't demand a mechanic's 
wages, and you look back and see your folly. How many 
are there in this boat ? Boys, take my advice : Don't get 
to knowing too much. If you get into that way, it is little 
use for a mechanic to have anything to do with you. 

THREE THERMOMETER SCALES. 

Much annoyance is caused by the great difference in 
thermometer scales in use in the different civilized countries. 
The scale of Reaumur prevails in Germany. As is wf^ll known, 
he divides the space between the freezing and boiling points 
into 80®. France uses that of Celsius, who graduated his 
scale on the decimal system. I'he most peculiar scale of all, 
however, is that of Fahrenheit, a renowned German physi- 
cist, who in 1714 or 1715 composed his scale, having ascer- 
tained that water can be cooled, under the freezing point 
without congealing. He therefore did not take the congeal- 
ing point of water, which is uncertain, but composed a mix- 
ture of equal parts of snow and salammonia, about — 14^ R. 
This scale is preferable to both those of Reaumur and Celsius, 
or, as it is called, Centigrade, because : i. The regular tem- 
peratures of the moderate zone move within its two zeros, 
and can therefore be written without + or — . 2. The scale 
is divided so finely that it is not necessary to use fractions, 
when careful observations are to be made. These advan- 
tages, although drawn into question by some, have been con- 
sidered so weighty, that both Great Britain and America have 
retained the scales, while the nations of the Continent use the 
other two. The conversion of any one of these scales into 
another is very simple. I. To change a temperature given 
by Fahrenheit's scale into the same given by the Centigrade 
scale, subtract 32^ from Fahrenheit's degxees and multiply 



30^ 

the remainder by |o The product will be the temperature 
in Centigrade degrees. To change from Fahrenheit's to 
Reaumur's scale, subtract 32° from Fahrenheit's degrees, and 
multiply the remainder by |. The product will be the tem- 
perature in Reaumur's degrees. 3. To change a temperature 
given by the Centigrade scale into the same given by Fahren- 
heit, multiply the Centigrade degrees by |, and add 32° to 
the product. The sum will be the temperature by Fahren- 
heit's scale. 4. To change from Reaumur's to Fahrenheit's 
scale, multiply the degrees on Reaumur's scale by ^, and add 
32° to the product. The sum will be the temperature by 
Fahrenheit's scale. Following is a table giving the equiva- 
lents in Centigrade, Reaumur and Fahrenheit, up to boiling 
point, which will be a convenience to all readers who do not 
like the labor of converting one scale to another : 

F. 

30.2 
32.0 
33.8 
35-^ 
37.4 
39-2 
41.0 
42.8 
44.6 
46.4 
48.2 
50.0 

h 

53-^ 
55.4 
57.2 

60.8 
62.6 
64.4 
66.2 
68.0 
69.8 
71.6 

73.4 

75.2 
77.0 
78.8 
S0.6 



c. 


R. 


F. 


C. 


R. 


—30 


— 24.0 


—22.0 


— I 


-^.8 


—29 


—23.2 


—20.2 





0.0 


^28 


—22.4 


^18.4 


I 


0.8 


—27 


—21.6 


—16.6 


2 


1.6 


—26 


^20.8 


—14.8 


3 


2.4 


—25 


— 20.0 


—13.0 


4 


3-2 


—24 


— 19.2 


—II. 2 


5 


4.0 


—23 


— 18.4 


—9.4 


6 


4.8 


—22 


-17.6 


-7.6 


7 


5-6 


—21 


—16.8 


-5.S 


8 


6.4 


—20 


— 16.0 


—4.0 


9 


7.2 


—19 


—15.2 


—2.2 


10 


8.0 


— 18 


—14.4 


—0.4 


II 


8.8 


— 17 


-13.6 


1.4 


12 


9.6 


-16 


—12.8 


3-2 


13 


10.4 


—15 


—12.0 


50 


14 


II. 2 


—14 


—II. 2 


6.S 


15 


12.0 


-13 


— 10.4 


S.6 


16 


12.8 


— 12 


-9.6 


10.4 


17 


.^3.6 


II 


-8.8 


12.2 


18 


14.4 


10 


~8.o 


14.0 


19 


15.2 


—9 


— 7.2 


15.8 


20 


16.0 


-8 


>-6.4 


17.6 


21 


16.8 


—7 


-5.6 


19.4 


22 


17.6 


—6 


-4.8 


21.2 


23 


18.4 


—5 


—4.0 


23.0 


24 


19.2 


—4 


—3-2 


24.8 


25 


20.0 


—3 


—2.4 


26.6 


26 


20.8 


- 2 


—1.6 


28.4 


27 


21.6 



304 

C. R- F. C. R. F. 

28 22.4 82.4 65 52.0 149.0 

29 23.2 81.2 66 52.8 150.8 

30 24.0 86.0 67 53.6 152.6 

31 24.8 87.8 68 54.4 154.4 

32 25.6 89.6 69 55.2 156.2 

33 26.4 91.4 70 56.0 158.0 

34 27.2 93.2 71 56.8 159.8 

35 28.0 95.0 72 57.6 161 6 

36 28.8 96.8 73 58.4 163-4 

37 29.6 98.6 74 59.2 165.2 

38 30.4 100.4 75 60.0 167.0 

39 31.2 102.2 76 60.8 168.8 

40 32.0 104.0 77 61.6 170.6 

41 32.8 105.8 78 62.4 172.4 

42 33.6 107.6 79 63.2 174.2 

43 34-4 109.4 80 64.0 176.0 
A4 35.2 III. 2 81 64.8 177.8 

45 36.0 1 13.0 82 65.6 179.6 

46 36.8 1 14.8 83 66.4 181. 4 



22.4 


82.4 


23.2 


81.2 


24.0 


86.0 


24.8 


87.8 


25.6 


89.6 


26.4 


91.4 


27.2 


93-2 


28.0 


950 


28.8 


96.8 


29.6 


98.6 


30.4 


100.4 


31.2 


102.2 


32.0 


104.0 


32.8 


105.8 


33-6 


107.6 


34-4 


109.4 


35.2 


III. 2 


36.0 


113.0 


36.8 


114.8 


37-6 


116.6 


38.4 


1 18.4 


39-2 


120.2 


40.0 


122.0 


40.8 


123.8 


41.6 


125.6 


42.4 


127.4 


43-2 


129.2 


44.0 


131.0 


44.8 


132.8 


45-6 


134.6 


46.4 


136.4 


47.2 


138.2 


48.0 


140.0 


48.8 


141. 8 


49.6 


143.6 


50-4 


145-4 


51.2 


147.2 



47 37.6 II6.6 84 67.2 183.2 

48 38.4 1 18.4 85 68.0 185.0 

49 39.2 120.2 86 68.8 186.8 
^o 40.0 122.0 87 69.6 188.6 

51 40.8 123.8 88 70.4 190.4 

52 41.6 125.6 89 71.2 192.2 

53 42.4 127.4 90 72.0 194.0 

54 43.2 129.2 91 72.8 195.8 

55 44.0 131.0 92 73.6 197.6 

56 44.8 132.8 93 74.4 199.4 
5,7 45.6 134.6 94 75.2 201.2 

58 46.4 136.4 95 76.0 203.0 

59 47.2 138.2 96 76.8 204. S 

60 48.0 140.0 97 77.D 206.6 

61 48.8 141. 8 98 78.4 208.4 

62 49.6 143.6 98 79.2 210.2 

63 50.4 145.4 100 80.0 212.0 
64 

WHY STEEL IS HARD TO WELD. 

A metallurgist gives, as a reason why steel will not weld as 
readily as wrought iron, that it is not partially composed of 
cinder, as seems to be the case with wrought iron, which 
assists in forming a fusible alloy with the scale of oxidation on 
the surface of the iron in the furnace. 



305 
DIFFERENT COLORS OF IRON, CAUSED Bl? 

HEAT. 



Deg. 
Cen. 


Deg. 
Fah. 


261 
370 


502 
680 


500 


932 


525 
700 
800 
900 
1000 


977 

1292 
1472 

1657 
1832 


1 100 


2012 


1200 


.2192 


1300 
1400 
1500 
1600 


2372 

2552 
2732 
2912 



/ 



Violet, purple and dull blue. 
Between 261'^ C. to 370*^ C. it 
passes to bright blue sea 
1^ green, and then disappears, 
f Commences lo be covered 
with a light coating of ox- 
■{ ide ; becomes a deal more 
I impressible to the hammer, 
i and can be twisted with ease. 
Becomes a nascent red. 
Somber red. 
Nascent cherry. 
Cherry. 
Bright cherry. 
Dull orange. 
Bright orange. 
White. 
Brilliant white-welding heat. 

] Dazzling white. 



TO DRAW FERRULES. 

A useful tool for drawing thimbles or ferrules out of loco- 
motive boiler tubes 
is here shown. It is 
an English inven- 
tion, and it is not 
stated that it is pat- 
ented. The tube ^/ 
is split in quarters on 
the end so that it 
can be easily slipped 
in. The rest of the 
device explains itself, 

as does the second figure also, which is another device f^^ the 

same purpose. 




3o6 
BELTING SHAFTING AT RIGHT ANGLES 

jn Fig. 1 of the illustration, A is the driver. The toelx, 
leaves the pulley at C, goes to the driven pulley, and then 
aown to the driver at h. In Fig. 2 this movement is re- 



19 



M 



If 



u 



r 



m 



9 



Fig. I. Fig. 2. 

•ersed. Fig. 3 is a side view of tlie driven pulley B, and Fig. 
4. shows the driving pulley A, with the driven pulley B in- 
side, so as to run in the one direction, while the dotted linesi 




B outside, so as to run the opposite way. Figs, t ands 

•how that centers of the faces of both pulleys must be in liao 



3^7 

with each other, and if this point is attended to the pulleys 
will run well together, although they may be of different 
diameter. 

AN EASY WAY TO LEVEL SHAFTING- 

The device here Illustrated for leveling shafting I have 
found to be very handy. The hangers A. are made of wood 
and are cut at an angle of 45 o at the top end, so that they will 
fit different sized shafts, and a slot is cut at (a) to receive the 
straight edge C. The hangers are placed on the shaft to loe 




tried, at any convenient place as near the bearings as possi- 
ble, and the straight edge placed in the slots, in which it 
should fit tight. Then by placing the spirit level D on the 
parallel part of the straight edge, it will be seen whether the 
shaft is level or not. It is best if the hangers be made of 
hard wood. 

A SELF-WINDING CLOCK MOVEMENT. 

A self-winding clock is now on the market and we present 
herewith an engraving of one. It is made by the American 
Manufacturing and Supply Co., Limited, lo and 12 Dey 
street, New York. Objection may be made to the employ- 
ment of a battery as an auxiliary, and therefore that the clock 



308 

fcnot self-winding, but the office of the battery is secondarf^ 

the operation of the clock opening the circuit while the bat- 
tery is used only to interrupt it. Appended is a descriptioc 
«f the movement: 




The wheels and arbors below the center are removed frt>m 
the clock. In their place a small electric motor is substituted. 
This motor connects Vv'ith a spring barrel on the center arbor, 
which incloses a spring six feet long, three-sixteenths of an 
inch in widtn and six-one-thousandths of an inch in 
(hicksiess. This sprinj^, at its innej' end, is attached 



309 

to the arbor, and at the ouver end to the periphery of the 
ppring barrel. The spring is coiled around the arbor many 
toes, but not so close as to produce friction between the 
coils; and being attached to the center arbor it follows that 
the inner end will unwind one turn every hour. "By a sim- 
jple attachment the electric circuit is made to pass into the 
motor already referred to, which quickly carries the spring 
barrel around once (being free on the arbor), and the outer 
'ud of the spring attached to its periphery with it. Upon 
he completion of one revolution of the spring barrel, as de- 
scribed, the electric circuit is broken and the motor stops. 
By this arrangement it will be observed that the inner end ot 
the spring always has a m.otion from left to right, or in the 
direction the hands are moving, and the outer end of the 
spring a motion in the same direction when the clock 19 
being wound. 

Now, since the winding is done in the same direction as 
the imwinding of the inner end, and the spring is SO wound 
originally as to avoid friction between the coils, it follows 
that the tension upon the train is absolutely uniform at all 
times whether the outer end of the spring is at a point of tem- 
porary rest or is being carried around the arbor at the tinae 
of winding, as above described. By actual experiment it is 
found that to obtain a given force at the escape wheel it is 
only necessary to apply a power in this manner at the center 
arbor equal to less than one- forty-sixth part of that used in 
the ordinary clock. The train work is not only shortened 
one-half, but the friction on the remainder is reduced in the 
proportion stated. 

The invention lies in bringing a motor and clock-wor"k 
gogether in a time piece, and is not limited to any particular 
levice. Experiments prove that a motor as constructed for 
this purpose cnn be run for one year at an expense of less 
than twenty-five cents; hence a clock may be sealed up and 
left to itself for a period of at lea^t one year with a certainty 
of closer time during tliat period than can be secured by any- 
other known method of giving time. In short, a common 
clock constructed on this principle has been found to keep as 
accurate time as one of the higher grades with gravity 
escapements, etc., run by the old methods. The electric 
motor is normally out of circuit, but at stated intervals, by 
the operation of the clock itself, the circuit is completed and 
the motor is thus set in motion. To be more exact we wili 
give a general description of the mechanism employed in the 
clock. Upon the center arbor there is placed a loose " arm ** 
between the hour wheel and the wheel carrying the spr 



3»o 

box. At one side of one of the " train plates " is secured 
an insulated spring connector, the free end of which extends 
to, and is within reach of, the " arm," when the same has been 
brought to a perpendicular position, which is done by means 
of a pin projecting from the hour wheel. 

When the hour wheel has thus brought the " arm " to an 
upright position and in contact with the insulated spnng 
connector, the circuit is completed through the motor, which 
at once commences to rotate the spring box one revolulion 
from left to right, or in the direction that the hpnds move. 
The spring box wheel also carries a projecting pm, but set at 
a less distance from the axis than the other pin. Now, as 
the motor continues to rotate, the spring box wheel, while 
the spring connector is resting upon the "arm," it follows 
that as soon as there has been one revolution of the spring 
box wheel the projecting pin upon this wheel will press the 
"arm" forward and out from under the spring connector, 
thereby breaking the circuit and stopping the motor. This 
arrangement prevents the possibility of the clock running 
beyond the regular limit for winding, and prevents the motor 
wnen once set IJQ operation from performing more than the 
work required, 

TESTS OF STEEL PIPE. 

The Riverside Iron Works, of Wheeling, W. Va., has 
carried out a series of interesting experiments to ascertain 
the relative corrosive action of water acidulated with nitric 
acid upon iron and steel plates cut from pipe. The Avater 
was acidulated with one part of strong nitric acid in ninety 
parts, the plates being of the same dimensions, free from 
scale and grease and polished bright. In each case the 
pieces cut from iron and steel pipe were hung side by side in 
the same acidulated water, the loss of weight being deter- 
mined at the end of twenty-four and of forty-eight hours. 
One test was made by exposing both surfaces and edges to 
the action of dilute acid, the result being that the loss in 
gi-ains after twenty-four hours was 3.6 in the case of iron 
from standard iron pipe, and 1. 15, or less than half, with steel 
pipe. In forty-eight hours the figures stood 6.53 and 2.21 
gx'ains, respectively. In a second test the edges of the pieces 
were protected from the action of the acid and the t wo oppo- 
site sides only exposed. In this test the loss of iron after 
twenty-four hours was 1.89 grains, against 0.49 grains with 
^'he steel, and after forty-eight hours 4.28 and 1.24, respect- 
yely. The dimensions' of the test-pieces were i}4 'nches 



3»i 



square by 3-16-inch thick. A series of comparative tests 
have also been made to ascertain the relative strength of the 
weld of Riverside steel and standard iron pipe. Two test- 
pieces were cut from Riverside pipe, mechanically lap-weld, 
with the weld at the middle, and in a similar way from 
mechanical lap-welded iron pipe, in each case with the weld 
in the middle. Not one of the tests broke at the weld, the 
steel showing a tensile strength of 52,400 and 66,330 pounds, 
with an elongation of 18.75 and 17.25 per cent, in 8 inches, 
while the iron pipe samples showed 62,480 and 35,240 pounds 
per square inch, and an elongation of 2.25 and 0.50 per cent 
Two samples from a sheet of Riverside steel lap-welded by 
hand, with the weld in the middle, showed a tensile strength 
of 51,860 pounds, and an elongation of 7 per cent, in 8 
inches, the fracture occurring at the weld. A second sample 
had an ultimate strength of 56,090 pounds, elongation 13 
per cent, and did not break at the weld. Iron plates cut with 
the grain and hand-welded have a tensile strength of 44,630 
and 43,500 pounds, respectively, with an elongation of 5- and 
4.25 per cent., both breaking at the weld. 

TOOL FOR COUNTER-BORING. 

The above is a sketcii of a tool that will be found very con- 
venient on many occasions, when 
counter-boring work in the drill 
press; usually such work is done with 
a cutter of the same shape as it is 
desired to have the finished work, 
when if there is any scale, as in cast 
iron, it is very difficult to get the cut- 
ter started. The tool in the sketch 
entirely obviates that difficulty, as 
only the points come in contact with 
the scale at first and are easily forced 
through it. Referring to the sketch, 
A is the end of a cutter-bar, B, the 
cutter, and C, the wedge for keeping 
the cutter in place. It will b* 
noticed that the teeth Z>, on one sid« 
of the bar will, as it is revolved, 
cover the space left by the part of 
the cutter on the other side of the 
bar, and thus rapidly remove the 
scale and metal, when the work 
may be finished by the ordinary flat 
cutter. 




312 

HOW TO MAKE A SMALL STORAGE BATTERY. 

A storage battery, or accumulator, to light an incandes- 
cent lamp of 4 candle-power, would not |go in an ordinary 
sized pocket, because one would require at least four cells, 
nd if the plates were made too small, the charge put into 
■ ^em would last scarcely a few seconds. The following di- 
..ections will enable any person to construct a storage bat- 
tery, which, when charged, will light a 4-volt lamp. 

The first thing to do is to procure of some dealer in elec- 
trical apparatus and material a hard rubber cell, about 3^ 
inches by 5 inches by i inch, having two compartments of 
equal dimensions. Such a cell can be purchased for about 
fifty cents. 

Next, cut four plates from one-sixteenth inch sheet lead, 
4 J^ inches by i X inch, having an ear to each ; punch as 
many holes in each plate as you can to within ^ inch from 
the ear or top end. Then fill up the holes, and also smear 
the plates with a thick paste of red lead (minimum) and di- 
luted sulphuric acid. • Cut out a piece from thin — -Y^ of an 
inch — hard wood, 3^ inches long and i inch wide ; pierce 
it with four slits large enough to allow the ears of the plates 
to come through (two to each cell), and, also, where con- 
venient, two holes should be made and fitted with glass tubes 
for the purpose of filling the cells. 

As soon as the red lead paste has become hard, plac thee 
four plates in their positions, and solder the ear of one plate 
to the ear piece of the next cell. This will leave one free end 
from each cell ; to these a wire or terminal should be sol« 
dered. Now cement on the top and cover all over, except 
the glass tubes, with a composition of one part melted- pitch 
and tw^o parts of gutta-percha. 

Having filled the cells three-quarters full with a 10 per 
cent, solution of sulphuric acid, connect the wires on ^ 
primary battery or small dynamo. Charge, discharge and 
reverse every three hours, and let the last charge remain in 
all night. Do this till you find your storage battery will 
ring a bell, with fifteen minutes' charging, for about ten. 
Then only charge one way, and mark the ends in some way 
so as to know where to connect one next time for chargmg. 

This battery, when completed, will light a 3 or 4 volt 
/amp well during intervals for about two hours. A similar 
cell, having four compartments instead of two, would suffice 
to operate an 8 or 9 volt lamp, or one of about 6 candle- 
Dower. 

Such a battery r '-^as just been described may be 



313 

veniently be formed by a ten-cell Daniel telegraph battery in 
about a fortnight's time. 

A storage battery of this size should never be charged 
until within an hour or so of its being wanted for use, as it 
will run down a little by short circuiting, owing to the damp- 
ness of the inside. 

Finally, it should be stated, that, before putting the plates 
in the cells for good, a piece of india rubber ought to be 
placed between the plates, as well as a piece on the two out- 
sides, and held by a piece of asbestos fiber. This prevents the 
plates from touching each other, and also keeps them from 
shaking from side to side. 

LUBRICATING WITPIOUT OIL. 

Several interesting facts in regard to cylinder lubrication 
were brought out at the recent meeting of the American 
Society of Mechanical Engineers, a'. Philadelphia. Among 
other things Mr. Denton stated as b.:s opinion that the fric- 
tion of an engine was independen" of the lead, and, among 
other things, presented the subjoined interesting table: 



Indicated H. P. 



84 

Unloaded 

23 

Unloaded 

347. . . . 
185 

181 

137 




Kind of engine. 



Westinghouse, 
12X11 inches, 
300 revolut's. 

Buckeye, 7x14 
inches, 280 re- 
volutions. 

Compound con- 
densing throt- 
tled. 

Compound con- 
d e n s i n g ex' 
pansion. 



This table, it will be observed, shows that the friction is 
actually less in all cases but one when the load is greatest, 
Mr. Denton thought that the friction of a piston in a cyl- 
inder was slight, and that lubrication did not bring about any 
noticeable result so far as this particular part was concerned. 
In support of these statements he cited first the case of an 
engine in which the steam of the same pressure was admitted 
to both cylinder ends at the same time The difference in 
area between the two faces of the piston^ owing to the pres 
ence of the piston-rod, and the consequ^.ntly greater effective 



314 

pressure on the back, as compared with the front face, caused 
the piston to move slowly to the front end of the cylinder. 
The friction, therefore, could not have been appreciable. As 
regards lubrication Mr. Denton gave an account of his 
experience with engines which had been cleaned out with 
ether, and in which no oil whatever had been used for months. 
The records obtained under such conditions, when compared 
with data from the same engines using oil in the cylinders, 
showed no difference worthy of special note. The fact that 
engines showed less friction under the heavier loads than 
under the lighter ones Mr. Denton explained by the assump- 
tion that the various journals, through the reversal of motia.?. 
of the reciprocating parts of the engines, developed a suc- 
tion-pump action, drawing in the lubricating oil, and that 
this action was more vigorous when the engines were fully 
loaded. 

CALKING. 

Calking is something that is not always -done as it should 
be. In fact, in some sections of the country it is done as it 
shouldn't be, about as emphatically as it is possible to do any- 
thing. The thing most particularly referred to in this con« 
nection, and the practice of which should bankrupt any 
boilermaker, is known as "split calking." To do calk- 
ing in the best manner, and as it should be done, the edges 
of the plates should be planed. They are planed in all first- 
class shops, and trouble caused by bad calking is something 
very rare with such work. But of course this refers to new 
work. Repair jobs, and boiler work turned out of the shops 
in remote sections of the country where planers are unknown, 
afford the demon of split calking a chance to get in his most 
effective work. He rarely neglects a chance that is offered 
him, Some one may inquire, what is split calking? To 
which we would reply, split calking consists in driving a thin 
caulking tool, scarcely one-sixteenth of an inch thick, against 
the edge of a sheet so that a thin section of the plate is 
driven in between the two plates, with the idea of making a 
joint tight. The result generally is that the plates are sepa- 
rated from the edge of the lap back to the line of rivets, some- 
times as much as one-thirty-second of an inch, the only bear- 
ing surface outside of the rivets being the portion split oft 
from the plate and driven in by the calking tool. This 
bearing surface may be an eighth of an inch wide, but it is 
apt to be much less, and no patent medicine yet discovered 
will keep the seam tight for any lengtli of time. When a 
boiler thus calked gets to leaking so badly that it can't be 



3IS 

fun, the boiler-maker is sent for, and he usually proceeds td 
do more split calking, and in a short time the boiler leaks 
worse than ever. In one instance one of our inspectors 
examined a boiler and found one of the girth seams leaking 
badly. It had repeatedly been calked in the above manner; 
so many times, in fact, had the process been repeated, that 
there was not enough of the lap to perform another opera- 
tion on. . He, therefore, gave instructions for putting on a 
patch, with a special caution to the owner, to whom he ex- 
plained the cause of the trouble, to allow no split calking to 
be done on it. On his next visit he examined the patch, and 
he declares that the boiler-maker had put in on it the worst 
iob of split calking he ever saw in his life. 

USEFUL NUMBERS. 

3.i4i5926=ratio of diameter to circumference of circle, 

.7854=ratio of area of circle to square of its diameter. 

33,000 minute foot pounds =1 HP. 

396,000 minute inch pounds— i HP. 

396,000 cubic inches piston displacement per minute of 
engine wheel would develop i HP. with i Tb. mean effective 
pressure on the piston. 

23,760,000 cubic inches piston displacement per hour of 
engine developing i HP. with i lb. mean effective pressure on 
the piston. 

859,375 pounds of water per hour at i Tb. pressure per 
square inch to give i HP. 

55 lbs. mean effective pressure at 600 feet piston speed 
gives I HP. for each square inch of piston area. 
0.30i030=natural logarithm 2. 



0.477I2I 


(t 


0.602060 


<( 


0.698970 


a 


0.778I5I 


tt 


0.845098 


u 


O.Q03090 


a 


0.954243 


a 


1. 000000 


(C 



<( 


3- 


i( 


4- 


a 


5- 


<( 


6. 


tt 


tf 




/• 


«< 


8. 


M 


9- 


(( 


10. 



2.3025851 times natural logarithm gives hyperbolic log ^ 
arithm. 

.5000000= sine of 30^ with radius I. 

.7071068 ^' 45Q " I. 

.8660254 " 6oC> « I. 

9,Goo to 13,000 feet per minute velocity of circular saw 
him. 

27,000 tbs. pcv scjuare inch tensile strength of cast ii'on. 



3^^ 

$0,<XX) tt)s. per square inch tensile strengtli of -wrought 
Iron. 

120,000 Tbs. tensile strength of steel. 
30,000 Tbs. tensile -strength of sheet copper. 
60,000 lbs. tensile strength of copper wire. 

100,000 lbs. per square inch=crushing strength of cast 
iron. 

35^000 Tbs. per square inch=crushing strength of wrought 
iron. 

225,000 lbs. crushing strength of steel. 

300 to 1,200 tons per square foDt crushing strength of 
granite. 

6.500 Tbs. per square inch ci ashing strengw!l of oak. 

(Above crushing strengths are for pieces not over 3 dia- 
meters in length. ) 

600 to 1,000 feet per minute of single leather belt i incb 
wide said to give i HP. on cast iron pulleys. 

2.645 ^t>s. per lineal foot of i incti round wrought iron. 

3.368 lbs. per lineal foot of i inch square wrought iron. 

40 lbs. per square foot of i Lnch plate wrought iron. 

2.45 lbs. per lineal foot of i inch round cast iron. 

12 times weight of pine pattern = iron casting. 

13 times weight of pine pattern = brass casting. 
19 times weight of pine pattern =lead casting. 
12.2 times weight of pine pattern = tin .casting. 

1 1.4 times weight of pine pattern =zinc casting. 
.06363 times square of inches diameter, times thickness in 
liches= weight of grindstone in pounds. 

.8862 times diam. of circle = side of a square equaling. 

,7071 times diam. of circle =side of inscribed square. 

1. 1283 times square root of area of circle =diam. of circle. 

57^ 2958 in. arc having length = radius 

.01 745 3 X radius=length of arc i deg. 

9.8696044=3. 141 5926'^ = n 2, 

1.7724538= v^ (3. 1415926)= vn. 

0.497i5=nat. log. 3.1415926. 

r 
.3l83i=reciprocal of 3. 1415926=— 

fi 
.cxD2778=i^36o=i-36o. 
II4.59=36o-^3.I4I5926. 
3i83Xcircumf.=diam. of circle. 
2786^ F. =melting point of iron. 
:-ioi6° F.=melting point of gold. 
1873° F.=melting point of silver. 
2160° F. =melting point of copper 



3^/ 

740^ F.=melting point of zinc. 
620^ F, =melting point of lead. 
475^ F.=melting point of tin. 
537 lbs. per cu. ft. =weiglit of copper. 
450 lbs. per cu. ft.=\veight of cast iron. 
485 lbs. per cu. ft. =:vveight of wrought iroil. 
708 lbs. per cu. ft.=weight of cast lead. 
490 lbs. per cu. ft.=weight of steel. 
27.684 cubic inches of water per pound at 32° F 
27.759 cu. in. water per lb. at 70^ 
036 lbs. per cu. in. water at 60^ F. 
62.355 lbs per cu. ft. water at 62 ^ F. 
59.64 lbs per cu. ft. water at 212 ^ F. 
.54 lbs. anthracite per cu. ft. 
40 to 43 cu. ft. anthracite per ton 
49 cu. ft. bituminous coal per ton. 
39.3635 inches = I meter. 
3.2807 feet = I meter. 
1.0936 yards = i meter. 
61.02 cubic inches = I meter. 
2.113 pints = I liter. 
1.057 quarts r== I liter. 

BUYING OIL AND COAL. 

There are many establishments which, when buying oil, 
u'Oal, and such supplies, consider merely the question of first 
cost irrespective of their economic value. The best is not 
necessarily the cheapest, nor is it necessarily the dearest. 
The true economic value is due to the service it will per- 
form, divided by the price. 

We will take the case of coal. Some coal will evaporate 
ten pounds of water per pound of coal under certain condi- 
tions, and others only seven. In the one case there will be 
2240X10=^22,400 pounds of water evaporated, and in the 
other only 2240X7 = 15,680 pounds, under the same condi- 
tions. If the first lot sold at $5.25 per ton, and the second 
at only $5 the first would be the cheapest, for in the one case 
(including freight and labor in stoking and cost of remov- 
mg ashes) we would get 22,400-^5.25=4,266.66 ;^ounds of 
steam per dollar's worth of coal, and in the other only 
1 5,680-^5 -=3, 136 pounds of steam per dollar's worth of coal. 
Not allowing for freight and the cost of removing ashes, and 
not considering the capacity of the boiler with good coal as 
compared with its capacity with poor, the first coal would be 
a scheap at $6.80 per ton as the second at $5 ; or, to put 



3i& 

it tlie other way, the poorer coal ought to be S'' ^^ hjj.SJ 

per ton to make it as cheap as the better material at $5.25. 

vVhen the other expenses are taken into consideration, the 
economy of buying the better coal becomes greater. 

In the matter of oils : these vary in their lubricating 
powers, in their coolness of running, and in their durability. 

We will consider two oils, one at 25 cents per gallon and the 
other at 30, having the same lubricating power and running 
equally cool under free feed, but one requiring 100 gallons to 
keep the friction down to a minimum and the other taking 
only 75 gallons to effect the same object. The relative 
economy of these two oils is not as 30 to 25, or as 120 to 100^ 
but as 30X75=2,250 to 25X100=2,500, or as 100 to 90; 
that is, the cost of the high-priced oil to effect a given desired 
condition is only .90 the cost of the poor oil to do the same 
thing ; then the economy is as 100 to 90. At this rate the 
better grade of oil would be as cheap at 
10X30 

^^33/i cents per gallon, 

as the cheaper at 25 cents ; or the lower grade would have* 
to be sold at 

9X25 

— 22 j^ cents per gallon, 

to bring its economy down to that of the better grade ; and 
this without counting freight, which, in many cases, should 
be added to the invoice price, or time in oiling, which is time 
lost. 

NOTES ON PATTERN-MAKING. 

Never work with a dull tool. 

Take time to sharpen and put your tools in good order; it 
saves time in the end. 

Above all, never use a dull or badly " set " saw. It will 
ruin your v/ork, sour your temper, and make you disgusted 
with the whole world. 

If you are varnishing or polishing a piece of work, have 
the room or shop Avarm, exclude draught and dust, and don't 
be in too big a hurry. 

If you are polishing in the lathe, see to it that ah dust 
and dirt are removed from the lathe-bed before you com- 
mence work. ( 

It is better, when possible, to polish all turned work in 
the lathe. It always has a better appearance for it. 

In making patterns for castings, if you have no experience 



3^9 

you had better consult some person who has had experience. 
Patterns are difficult things for amateurs to make if they do 
not understand the principles of molding and founding. 

White pine or mahogany makes the best work for pat- 
terns. Lead, brass, copper and sometimes plaster of Paris 
are used for making patterns; especially is this so for small 
fine castings. 

Shellac varnish is the best material for coatijiq; pat- 
terns. 

Beeswax may be used for stopping up holes or to cover 
defects in patterns if it is coated with shellac varnish after- 
ward. The beeswax will " take " the varnish readily, and 
will not cling to the -'sand," like ordinary putty. 

Shellac varnish may be mixed with a little lampblack to 
give it body and make a black pattern. 

Sometimes pattern-makers use stove polish or "black 
lead," as it is called, to finish their patterns. It is applied 
nearly dry, then polished with a brush. 

Wood used for patterns must be of the very best finish, 
straight grained, free from knots or shakes, and well sea- 
soned. 

A clean pattern gives a clean casting, and much labor 
may be saved by making the pattern the right size, and 
smooth and clean. 

After patterns have been used they should be kept in a 
dry plfice, as damp will distort and otherwise injure them. 

Always make a drawing of patterns before making. Much 
time and labor will be saved. 

Where patterns part in the center they should be made 
to separate easily. 

Put on your best workmanship when pattern making. 

AN INTERESTING EXPERIMENT. 

You think you stand pretty straight, don't you? Well, 

just back up against the wall of a room and bear against it 

all over ; you will find there more buckles, short bends an4 

offsets between your head and your heels than you had any 

idea of. 

While you have your heels against the baseboard, keep 
them there, and reach over forward and touch your fingers to 
the floor, if you want a specimen of upset gravity. 



A steel wire nail mill has just begun work at Hamilton, 
Ont, The output at present is a ton a day. 



320 

THINGS TO REMEMBER ABOUT SHAFTING. 

Don't buy light hangers, and think that they will do well 
enough, when your own judgment tells you that they will 
spring. 

Remember that shafting is turned one-sixteenth inch 
smaller than the nominal size. 

Cold-rolied and hot-rolled shafting can be obtained ihe 
full size. 

The sizes of shafting vary by quarter inches up to i.iree- 
and-a-half inches. 

The ordinary run of shafting is not manufactured longer 
than from 1 8 to 20 feet. 

For line shafts, never use any that is smaller than one- 
and-eieven-sixteenth inches in diameter, as the smallest 
diameters are not strong enough to withstand the strain of 
the belts without springing. 

) The economical speed of shafting for machine shops has 
been found to be from 125 to 150 revolutions per minute, 
and for woodworking shops froni 200 to 300 revolutions. 

A jack-shaft is a shaft that is used to receive the entire 
power direct from the engine or other motor, which it delivers 
to the various main shafts. 

Keep the shafting well lined up at all times, as this will 
ward off a breakdown, and avoid a waste of power. 

Know that the pulleys are well balanced before they are 
put in position, as a pulley much out of balance is quite a 
sure method to throw shafting out of line. 

Look to the pulleys, and see that they have been bored to 
the size of the shaft, for unless this is done the pulley may be 
out of center on the shaft and prevent smooth running. 

If possible, apply the power to a line of shafting at or near 
the center of its length, as this will enable you to use the 
lightest possible weight of shafting. 

Hangers with adjustable boxes will be found to be the 
most convenient for keeping the shafting in line. 

Keep your drip-cups cleaned, and Jo not allow them to 
overflow or get loose. 

Have a supply of tallow in the boxes ; ni case of acciden- 
tal heating it will melt and prevent cutting ; this rule, while 
good for general use, applies particularly to special cases wbeie 
there is a supposed liability to heating. 

Never lay tools or other things on belts that are standing 
Still, for they may be forgotten and cause a breakdown when 
the machinery is started. 

Don't attempt to run a shaft in a box that is too large or 



32X 

too small, as you wiU waste time and fail to secure good re* 

suits. 

A loose collar held by a set screw will cause the collai 
to stand askew, and it will cut and wear the box against 
whick it runs. 

In erecting a line of shafting, the largest sections should 
be placed at the point where the power is applied. The 
diameter can then be gradually decreased toward the extrem- 
ities remote from this point. 

Don't put loose bolts in plate couplings, as this will give 
no end of trouble in cutting, shearing and the wearing away 
of the bolt holes. 

Don't think that because your shafting has been weli 
erected and you oil it regularly, that it will never need any 
inspection or repairs. 

Don't try to economize in first cost by having long dis- 
tances between hangers, for a well supported shaft will 
always do the best work ; short shafts are the surest to be 
straight and to remain so. ''^ 

The length usually adopted for shafting bearings is twice 
to four tniies the diameter of the shaft, varying with the 
diameters of '.haft, kind of bearings and the material used in 
them. Large shafts in the gun-metal or bronze boxes may 
have bearings only twice their diameter in length. Cast iron 
bearings up to and including three inch shafts are often made 
four diameters of the shaft in length, particularly for self- 
adjusting hangers. 

If Babbit is used for the boxes, use onlv a good metal; 
do not adopt the common mixture of tin, antimony and 
lead. 

Insist upon having good iron in your shafting, as the 
bearings will take a finer polish, and you will nut be subject 
to sudden ruptures. 

If the strain on a pulley is so great that the set-screws 
already in will not hold it, do not let them score into the 
shaft, but put in an extra screw, or cut a key-way and put in 
a key. 

The width of a key-v/ay should be one-quarter of an inch 
for each inch of diameter of the shaft. 

'I'he depth of a key-way is one-half its width. 



322 

WORKSHOP JOTTINGS. 

To P7'epai'e Zinc for Painting — Apply sulphuric acid 
and water for a quarter of an hour ; then wash off clean with 
water and dry. 

Moisture-Resisting Glue — A glue which is proof againsj 
moisture may be made by dissolving i6 ounces of glue in 3 
pinfes of skim milk. If a stronger glue be wanted, add 
powdered lime. 

A Good Lubricator — It may not be generally known that 
tallow and plumbago thoroughly mixed make the best lubri. 
cator for surfaces when one is w^ood or when both are wood. 
Oil is not so good as tallow to mix with plumbago for the 
lubrication of wooden surfaces, because oil penetrates and 
saturates the wood to a greater degree than tallow, causing it 
to swell more. 

To Prevent Metals Rusting — The following is said to 
be a good application to prevent metals rusting: Melt i oz. 
of resin in a gill of linseed oil, and while hot mix with it two 
quarts of kerosene oil. This can be kept ready to apply at 
any time with a brush or rag to any tools or implements 
required to lay by for a time, preventing any rust, and saving 
much vexation when the tool is to be used again. 

7<? Prevent Slipping of Belts — Belts conveying power 
are very apt to slip on pulleys, but a new pulley has been 
devised to prevent this. The pulley is covered with per- 
forated sheet iron one-sixteenth of an inch thick, which is 
riveted to the pulley. The tension of the belt causes it to 
grip slightly the holes, and thus slipping is avoided, while at 
the same time the pulley is strengthened. 

To Calculate Water in a Pipe — To calculate roughly the 
quantity of water in any given pipe or other cylindrical ves- 
sel, it is only necessary to remember that a pipe one yard, or 
three feet, long will hold about as many pounds of water as 
the square of its diameter in inches. Thus: If we have a 
pipe 20 inches in diameter and 16 feet long, we have simply 
to square 20 (20^=400), and multiply the result by the 
number of times 3 feet is contained in 16 feet=5j^ times; 
hence, 400x53^=^2,133 pounds. By increasing the result by 
2 per cent., or I -50th, a more nearly exact figure _f an be 
obtained. '^ 



323 
BRASS AND ITS TREATMENT. 

Brass, as previously stated, is perhaps the best known ant} 
most useful alloy. It is formed by fusing together copper 

and zinc. Different proportions of these metals produce 
brasses possessing very marked distinctive properties. The 
portions of the different ingredients are seldom precisely alike; 
these depend upon the requirements of various uses for which 
the alloys are intended. Peculiar qualities of the constituent 
metals also exercise considerable influence on the results. 

Brass is fabled to have been first accidentally formed at the 
burning of Corinth, 146 B. C, but articles of brass have been 
discovered in the Egyptian tombs, which prove it to have had 
a much greater antiquity. Brass was known to the ancients 
as a more valuable kind of copper. The yellov/ color was con- 
sidered a natural quality, and was not supposed to indicate an 
alloy. Certain mines were much valued, as they yielded this 
gold-colored copper, but after a time it was found that by 
melting copper with a certain earth (calamine), the copper 
was changed in color. The nature of the change was still 
unsuspected. 

Alloy of copper and zinc retain their malleability and 
ductility when the zinc is not above 33 to 40 per cent, of the 
alloy. When the zinc is in excess of this, crystalline character 
begins to prevail. An alloy of one copper to two zinc may 
be crumbled in a mortar when cold. 

Yellow brass that files and turns well may consist of cop- 
per 4, zinc I to 2. A greater proportion of zinc makes it 
harder and less tractable; with less zinc it is more tenacious 
and hangs to the file like copper. Yellow brass (copper 2, 
zinc i) is hardened by the addition of two to three per cent, 
of tin, or made more malleable by the same proportion of 
lead. 

There w^ould be less diversity in the results of brass cast- 
ings if what was put in a crucible came out of it. The vola- 
tility of some metals, and the varied melting points of others 
in the same mix, greatly interfere with the uniformity in 
ordinary work. Zinc sublimes *(burns away) at 773 to 800 
degrees, while the melting heat of the copper — with which it 
should be intimately mixed in making brass — is nearly 1,750 
degrees. Copper, zinc, tin and lead in varying proportions 
form alloys, always in definite quantity for a given alloy. 
The ease with which some of the metals are burned away at 
comparatively low temperatures renders it a very easy mat- 
ter to make several different kinds of metal with (he same 
erv ':h)-^:^ ) ::'irs, and the great difficulty in get- 



324- 

ting bearing brasses uniform in quality causes some engineers 
to babbitt all bearings as the best way to insure Uiiiformity. 
One lot of castings may be soft and tough, another hard, 
and so on. 

Zinc is added the last thing as the crucible comes out of 
the furnace, and the mixing of the mass is a matter of uncer- 
tainty. If the metal is too hot for the zinc a large percent- 
age goes off in the form of a greenish cloud of vapor, and 
the longer the stirring goes on the more escapes. The two 
metals which enter into the composition of brass have an 
affinity for each other, but they must be brought into inti- 
mate contact before they will combine. Some brass founders 
use precautions to prevent volatilization of the more fusible 
metaJs, introducing them under a cover ^f powdered charcoal 
on top of the copper. 

" Brass finisher " is a term many understand as applied 
only to those who produce highly-finished brass work ; but it is 
not so ; the brass finisher's work is not the superior class of 
work supposed, most of it beinp- comprised in gas fittings, 
ormolu mounts, etc., but the nignest class of brass finishing 
is a totally different process. Fittings for gas work, all 
finished well enough for their several purposes, and as well 
done as the price paid for them will allow, as well as the 
mountings for furniture, must obviously be produced at a low 
price, in order to supply the demand for cheap work of this 
character, most of which is simply dipping, burnishing and 
lacquering. 

Let us follow the process of finishing the highest class of 
brass work. Before commencing to polish, all marks of the 
file must be removed, and this is done thus : Having used a 
superfine Lancashire file to smooth both the edges and surfaces, 
take a piece of moderately fine emery paper and wrap i^ 
tightly, once only, round the fiJe. By having many folds 
round the file the work becomes rounded at the edges, 
and so made to look like second-rate things. Some Ui:^e 
emery sticks, made of pieces of planed wood about ^i 
inch thick and ^ inch wide, quite flat on the surfaces. 
They are covered with thin glue, and the emery powdered onto 
them, and then allowed to dry hard. Most common work 
is rubbed over, not to say finished, Avith emery cloth. This 
will not do for good work. The paper folded once round 
the file is used in a similar manner to the file, and when the 
file-marks disappear, and the paper Js worn, a little oil is 
used, which makes it cut smoother, ^he edges and surfaces 
being prepared to this extent, tiic cages must be finished- 
To effect this take a piece of flat, soft wood, and apply t<^ -ts 



3^'5 

surface a little fine oil-stone powder; be sure that it is quite 
clean, as it is very annoying to make a deep scratch in the 
work just as it is finished; perhaps so deep that it will re- 
quire filing out. 

FACTS ABOUT A WATCH. 

The watch carried by the average man is composed of 
ninety eight pieces, and its manufacture embraces more 
than 2,000 distinct and separate operations. Some of the 
smaller screws are so minute that the unaided eye cannot 
distinguish them from steel filing or specks of dirt. Under 
a magnifying glass a perfect screw is revealed. The slit in 
the head is two one-thousandths of an inch wide. It takes 
308,000 of these screws to weigh a pound, and a pound is 
worth $1,585. The hairspring is a strip of the finest steel, 
about dYz inches long, and one-hundredth inch wide and 
twenty-seven ten-thousandths inch thick. It is coiled up in 
a spiral form and finely tempered. 

jThe process of tempering these springs was long held as a 
secret by the few fortunate ones possessing it, and even now 
it is not generally known. Their manufacture requires 
great skill and care. The strip is gauged to twenty one- 
thousandths of an inch, but no measuring instrument has 
yet been devised capable of fine enough gauging to deter- 
mine beforehand by the size of the strip what the strength 
of the finished spring will be. A twenty one-thousandth 
part of an inch difference in the thickness of the stop makes 
a difference in the running of a watch of about six minutes 
an hour. 

The value of these springs, when finished and placed in 
watches, is enormous in proportion to the rr^aterial from 
which they are made. A comparison will give a good idea. 
A ton of steel made up into hairsprings when in watches is 
worth more than 12^^ times the value of the same weight in 
pure ffold. Hairspring wire weighs 1-20 of a grain to an 
inch. One mile of wire weighs less than half a pound. The 
balance gives five vibrations every second, 300 every min- 
ute, 18,000 every hour. 432,000 every day and 157,680,000 
every year. At each vibration it rotates about 1^ times, 
which makes 197.100,000 revolutions every year. 

>In order that we may better understand the •stupendous 
amount of labor performed by these tiny works, let us make 
a pertinent comparison. Take, for instance, a locomotive 
with six-foot driving wheels. Let its wheels be run until 
they have given the same number of revolutions that a 
watch does in one j^ear, and they will have covered a dis- 
tance equal to 28 complete circuits of the earth. All this a 
watch does without other attention than winding once every 
14: hours. 



326 
METAL-WORKING DIES AND THEIR QSES. 



BY HENRY LONG. 

In the following pages, which have been specially prepared 
for this work, will be found a condensed description of the 
commoner kinds of dies now in use for sheet-metal w^ork. 
There being several kinds of punching presses, I will specify 
the variety m which each die can be used as I describe it. 
The commonest in use is the simple cutting-die, and I will 

describe it first. It can either 
be made by welding a steel ring 
of the shape desired on a 
wrought iron plate, and then 
dressing the hole out roughly 
to pattern while hot, or by 
drilling out a hole of the shape 
required through a piece of 
flat steel of proper dimensions, 
and then dressing it out with 
files, etc. , to exact size. ^While 
the former plan is most expen- 
sive, it is the best in regard to 
wear and quality of work. Fig. i represents a die of this 
kind. The forging for this die would be made as I explained 
above; that is, by welding a steel ring of the shape of 
tt.e pattern on an iron plate, and cutting the hole 
through the iron afterward. The punch for this would be 
made similarly, only that the ring is the shape of pattern 
outside, and after welding to the iron plate it is trimmed off 
outside. There is also a shank to be welded on the other side 
of plate, as nearly central as possible, and large enough to 
finish up easily to size required. In making this die the two 
faces are planed off clean, and then the pattern is laid on top 
face and the die is marked from it. When this is done, it is 
put in the shaper and planed out to the marks, care being 
taken to throw the work forward in the chuck to ^ive about 




16 



in. clearance to the inch, in depth. 



It is now filed out and champfered off on face, as shown, 
tffeface being hollowed out 3V' on three or four sides after- 
ward to give it a shearing edge. It is now ready for tempering. 
As the tempering requires great care it is very necessary to 
watch your heat closely, and while making it even, do not 
heat any higher than necessary, and plunge it carefully into 
cold soft water with one edge down, keeping it in there until 
perfectly cold. '^ Now take it out and polish the face and 
inside well, and reheat very evenly as before until you observe 



327 



inside the marks and 




a dark straw color, when you can cool it off, at th«.: is. con- 
sidered a good temper, and one that will stand wear without 
breakmg. The punch is pared off on both sides and shank 
turned up to size, and then the die is laid on it face to face 
and the shape marked out. Now it is shaped off to the lines 
and fitted closely in the die, the inside edge of punch being 
afterward champfered off as shown. This die can be used in 
any press, and is particularly designed for light metals such 
as zinc, tin, etc. A flat-cutting die would be made by taking 
a piece cut from the bar at least i}{" longer and 
wider than your pattern, and, after planing it, lay 
your pattern on and mark the hole. Then drill around 

file out in same way as you do 
the other. The punch would be 
made same as last, but without 
champfering off the edge. This die 
can be used in any press, and is 
designed for heavy work, such as 
hard brass, steel, etc. Sometimes 
there may be some narrow or weak 
part in the die which is likely to 
break out in time, in which case it is 
economical to insert a plug as shown 
in Fig. 2. Of course these plugs 
can be renewed as often as necessary without disturbing 
the form of the die. For round holes of small size, a steel 
plug is fitted in a soft steel plate, and the hole drilled and 
reamed through it, after which the plug is tempered. 

The punch is simply a socket with a set screw in which 
round steel of the right size is used, in this way saving any 
turning or fitting. Sometimes a gang of punches is used, as 
is shown in Fig. 3, for which a special punch is designed. In 
this, the shank is a separate piece, and 
has a dove-tailed groove planed through 
it. This groove should be from ^^' to 
}4'^ larger in every way than the dimen- 
sions you wish to punch. It should also 
have 3^7,'' draft, or taper endwise to allow 
of a driving bit on the plate fitted in. 
This plate should be }4" thick at least. 
You first drill all the holes in your die 
in the right position, and after reaming 
Fig. 3. them out, harden and temper it. You 

now place this plate, which you have fitted in the shank, on 
the face of the die in its true position and fasten it securely 
there. The next thing is to run the drill you used on the 



Fig. 2. 







328 

die, through tne die holes, and mark their exact position on 
this plate. When this is done, remove the die and drill the 
holes through from these marks, and countersink them from 
behind. Now, the stripper or guide, which should be about 
^" thick, is fastened on in the position you wish it, and 
marked and drilled in the same way. The wire punches are 
made by riveting over a head on one end and then driving 
them in from the back, afterward filing off any superfluous 
metal which extends above the back. When you have made a 
gauge and placed it under the stripper, fastening securely, the 
die will be finished. 

The punches should be filed to an even face, and then hol- 
lowed out a little to give more ease in cutting. All the dies 
mentioned thus far can be used in any ordinary press. V7e 
will now take up the different kinds of form- 
ing dies. 1 nere are only two kinds, half- 
round and square; all others are modifica- 
tions of these-. The depth of a half-round 
forming die should be two-thirds of the 
diameter to give the best results,. and the 
punch should go down into the groove as 
shown in Fig. 4. A mandril is necessary to 
form the work over in the die. A square 
or box-forming die is simply a square hole 
of the right size, cut through the die, per- 
fectly parallel, and with the upper corners 
rounded a little. If a smooth flat 
bottom is required it is usual to make 
thedieofthinest steel, and put a plate 
under it as in Fig. 5, with a pad and 
spring, to throw it out. The punch 
is size of the inside of box, and a close 
fit. A die for formmg a shape at any 
angle is simply a groove planed thro' 
the block and having a punch to fit 
it. Fig. 6 is a view of a common 
form of drawing die for deep work. 
They are used for making caps, cart- 
ridge cases, etc. It consists of a 
round disk of steel about J^"deep 
with a hole the size of shell required bored in it . 

This hole is well rounded off at the corner, and counter- 
oored from the bottom with a square, sharp shoulder for 
stripping the work off the punch after it has passed through 
the die. A cast-iron holder with set screw is generally used 
with these dies for convenience in changing. The punch is 




Fig. 4. 




Fig. 5. 




Fig. 6. 



329 

fitted into a socket in the shank and held by 
a set screw. It is rounded on the corners to 
give the metal a better chance to turn up 
around it. When the punch and die are set 
the blank is laid on the die, and the punch 
should be tight enough to carry it through 
without a wrinkle. If the shell is not long 
enough after this operation, make a die a 
little smaller and a punch the same, and after 
annealing the shells pass them through it. By 
repeating this operation you can produce 
shells of almost any length. Sometimes it is 
necessary to make a die to perform some 
operation on the edge of a box which has already betxi formed 
In this case the die is m.ade in such a way that the box can 
be put on it, thus placing the die on the 
inside. A hub is made the shape of the 
box, and with the die dovetailed into its 
upper side, a hole being bored down 
through the hub to allow the cuttings to 
fall through. This hub is fitted into a 
special holder as shown. The punch is 
made in the same way as others.^ These 
dies can be used for any operation that 
a flat die performs, such as cutting, form- 
ing, etc. As I have given a description 
of the different forms of simple dies, I will now explain some 
double and combination dies. A double die is two distinct 
dies in one plate, and it may be extended to include three 
or four, although the work gets complicated in this case, 

and the economy is doubtful. 

This xdie may be composed 
of two cutting dies, or one cut- 
ting and one forming die, or, in 
fact, any combination which 
may seem desirable. It is gen- 
erally used for cutting dies, 
such as washers, etc. Fig. 8 
shows the plan of one of these 
dies designed to make a washer. 
The first punch is the size of 
the hole in the washer and the 
second cuts out the washer it- 
self. The punches are set in 
a long, flat socket, fastened with 
screws. The main point in these 





Fig. 8. 





a 




— if-H — 



330 

dies is to get them correctly spaced so as to cut out all the 
stock. They can be used in a power or foot press. A com- 
bination die is one which performs two or more operations in 
one die. Fig. 9 is one of these, designed to make a black- 
ing-box cover. In this die the punch comes down and cuts 
out the blank which is 
immediately gripped be- 
tween the two face a 
and ^, and held firmly 
enough to prevent 
wrinkling, but still to 
allow of its being drawn 
through and over the 
form which is in the 
center of the die. 
When tne press is on the 
return stroke, the ring d 
follows the punch up and 
pushes the cover off 
again, w^iile the pad in 
the punch does the same 
there, thus having the 
cover loose on the top 
of the die. These dies 

tig. 9. 
must be operated in a power 
press, or one specially de- 
signed for the purpose, and 
they are more conveniently 
worked in an inclined than 
a horizontal press, as the 
work will then fall off by the 
force of its own gravity. 
-t Fig. 10 is a die of the 
J same class, but with another 
operation added. It is de- 
S'igned to make a pepper-box 
cover, and perforates four 
holes in it after it is drawn. 
The punch, as you will per- 
ceive, is entirely different in 
its construction. The die is 
the same, excepting that four 
cutting holes or dies are 
drilled in the top of the form 



LI^fflE 



'^^ 



ri 



:j 



Fig. 10. 



331 

or plug, and the inside is bored out to allow the cuttings to 
fall through. The stub is also bored out for the same reason. 
In the punch a is the shank, bored out as shown, b is the 
cutting edge or punch proper ; it is bored or chambered out 
for the pad c to work in it. ^ is a plate that screws into the 
top of the punch b^ to act as a back for the pad c to press 
against, and also as a holder for the four small punches. It 
has three holes in it, through which short pins work to com- 
municate the power of spring E to the pad c. i^ is a washer 
under the spring, and 6^ is a plug or pin that screws in the top 
of shank, and extends down to the plate <f, against which 
it presses, in this way hold-ing the small pin punches down 
to place, and guiding and regulating the spring at the same 
time. The operation of the die is the same as Fig. 9, only 
that after the tin has been drawn down its full length, the 
small punches cut the holes through the top, and then the 
pad c acts as a stripper for these punches at the same time 
as it punches the cap out of the large punch. 

Fig. II represents a die for doing the same work, but in 
what is called a cam or double-action press. These dies are 

much simpler and 
cheaper to make and 
do equally good work 
with the others. The 
piece A is the cutting 
punch, and works in 
the die B. After cut- 
ting the blank it 
passes down until it 
presses the blank 
against the face shown 
on the inside of the 
die. While it is hold- 
ing the blank firmly 
there the forming 
punch C passes down through the cutting punch and 
forces the tin down through the inside die B, in this way 
forming it into any shape desired. In passing up again it 
strips the box off against the underpart of the die, allowing it 
to fall into a box underneath. This covers the list as an- 
nounced in the beginning of this article, and although the 
different kinds of dies are endless, the foregoing description 
will enable the reader to judge of the best way of doing work, 
and there is hardly any pattern which cannot be produced by 
one or more of these dies in combination. 






Fig. II. 



332 

RULE TO FIND THE STRENGTH OF BOILER 
SHELLS AND FLUES. 

The pressure for any dimension of boiler can be ascertained 
by the following rule, viz. : 

Multiply one-sixth (j/^th) of the lowest tensile strength 
foui¥i stamped on any plate in the cylindrical shell by the 
thickness — expressed in inches, or parts of an inch — of the 
thinnest plate in the same cylindrical shell, and divided by the 
radius or half diameter — also expressed in inches — and the 
quotient will be the pressure allowable ])er square inch c»f sur- 
face for single riveting, to which add twenty per centum for 
double riveting. 

Boilers built prior to February 28, 1872, shall be deemed 
to have a tensile strength of 50,000 pounds to the square inch, 
whether stamped or not. 

For cylindrical hoiXev Jlues over 16, and less than 40 inches 
in diameter, the following formulas shall be used in determin- 
ing the pressure allowable. 

Let D = diameter of flue in inches. 
1760 = A constant. 

T = thickness of flue in decimals of an inch, 
P = pressure of steam allowable, in pounds^ 
1760 

= F, a factor. 

D 

.31 = C, a constant 
FXT 

Formula : = P. 

C 

EXAMPLE. 

Given, a flue 20 inches in diameter, and .37 of an inch in 
thickness ; what pressure could be allowed by the inspectors? 
1760 88X.37 

F = = 88 i then, = 105 + pounds as the allowa- 

20. .31 ble pressure. 

TO CALCULATE THE SPEED OF A BELT. 
To find the speed a belt is traveling per minute, multiply 
the diameter in feet of either pulley by 3. 7 times its revolutions 
per minute ; the result is the feet travel of belt per minute if 
there is no slip. At the recent " Invention? Exhibition " in 
Liverpool, the indicated horse-power transmitted by the belt- 
ing averaged, on trial, per one inch width of belt a horse 
power, a speed of 200 feet per minute ; it would seem hat a 
liberal factor of slip should be allowed outside of this. 



6SS 



STZBS 


AND WEIGHT OF i 


SHEET TIN. 




?<o. of 


Dimensions. 


Wt. 


Mark. 


sheeTw 






of 




m Bojfe. 


Length 


Brdth. 
Inches. 


Box. 






Inches. 


Lbs. 


IC 


225 




10 

9V, 

9'A 
10 


112 


lie 


105 

98 

140 


IIIC 


a 




IX 


a 


IXX 


u 


a 
a 


161 


IXXX 


182 


IXXXX..... 


ti 


u 


(( 


203 


DC ,.. 


KX> 


z9% 
il 

it 


12X 


126 


DX 




DXX 


147 


DXXX 


a 


a 


a 


168 


DXXXX 


ii 


il 


(( 


189 


5 l^C 

i DX 

. DXX. 

i DXXX 


2Q» 


15 


II 


1 63 


A 


a 


a 


189 


11 


u 


a 


210 


a 


(( 


a 


231 


\ DXXXX... 

frw 


6( 


(( 


li 


252 


225 


I nU 


10 


112 



The following tai:>ic^ showing the number of pomids pei 
fe»t m various woo(^, in different stages of dryness : 



Green. 

White ash 4^ 

Gray ash „ . . . 4}^ 

Birch 5X 

3asswood 'X}/ 



Cottonwood 3^ 

Cherry ^ 

Chestnut 4^ 

Soft elm 4 

Rock elm 5 

Hickory 5^ 

Plard maple 5X 

Bird's-eye maple .... 5^ 

Curly maple 43^ 

White oak 6" 

Red oak K%, 

^amwT* J 

VValnuli. . .^^.^ ^^ .. .. 6 

VVhitewoed ^% 



ipping 


Thoroughly 


Kiln 


dry. 


air dried. 


dried. 


4 


z% 


2 4-5 


31^ 


J 


2K 


4K 


4 , 


3^, 


3 


2}4 


2>i 


3 


2K 


2/8 


4>^ 


3H 


3 ^ 


J>^ 


2% 


2^ 


3J^ 


3 , 


^Yz 


4X 


3^ 


A 


45^ 


4 


3J^, 


4J^ 


31^ 


3 


4X 


3^ 


3 ^ 


4 


3.^ 


2^ 


s 


4>^ 


4 


4^ 


Z% 


3 


4 


3 


23^ 


5 


4 , 


3U 


3,'^ 


2^ 


2% 



334 



CALIBER AND WEIGHTS OF LEAD PIPES. 





WEIGHT 


1 


WEIGHT 


CALIBER. 


PER 1 


CALIBER. 


PER 




FOOT. 




FOOT. 




LBS. 


oz. 




LBS. 


oz. 


14^ in. tubing 




6 1 


iX in. aqueduct. . . 






^ in. aqueduct .... 




« ! 


ex. hght 


3 


8 


light 




12 ; 


light 


4 




medium 


I 




medium 


5 




strong 


I 


8 


strong 


6 




ex. strong. . . 


2 




ex. strong, . . 


7 


8 


1/2. in. aqueduct .... 




10 


134; in. light 


3 


12 


ex. light 




12 


light 


4 


8 


light 


I 




medium 


5 


8 


medium 


I 


4 


strong 


6 


8 


strong 


I 


12 


ex. strong... . 


8 




ex. strong. . . 


2 


8 


2 in. waste 


3 




^ in. aqueduct. .... 




12 


2 in. ex. light 


4 




ex. light 


I 


4 i 


light 


5 




light 


I 


12 


medium 


7 


8 


medium 


2 




strong 


8 




strong 


2 


8 


ex. strong. . . 


9 




ex. strong. . . 


3 




2^ in. 3-16 thick. . 


8 




^ in. aqueduct. . . . 


I 




X thick 


II 




ex. light 


I 


8 


5-16 thick. . . 


14 




light 


2 




y% thick 


17 




medium 


2 


4 


3 in. waste 


S 




strong 


3 




3-16 thick.. . 


9 




ex. strong. . . 


3 


8 


X thick 


12 




^ in. aqueduct .... 


I 


8 


5-16 thick. . . 


16 




ex. light 


2 




^ thick 


20 




light 


2 


8 


3/^ in. X thick. . . . 


15 




I in. aqueduct 


I 


8 


5-16 thick... 


18 




ex. light 


2 




y% thick 


21 




lignt 


2 


8 


4 m. waste 


S 


1 


medium 


3 


4 


X thick 


16 


1 


strong 


4 




5-16 thick. . . 


21 


1 


ex. strong. . . 


4 


12 


^ thick 


2S 


1 


iX in- aqueduct 


2 




7-16 thick.. . 


30 


1 


ex. light 


2 


8 


4X in. waste 


6 


I 


%ht 


3 




5 Tn. waste 


8 


1 


medium 


3 


12 






1 


Strong 


4 


12 






1 


ex. strong, . . 


6 








-M 



335 
WEIGHT OF CIRCULAR BOILER HEADS. 



Diam. 
in 




Thickness 


of Iron. — Inches. 




inches. 


3-16 


. X 


5-16 


n 


7-16 


y^ 


9-16 


i6 


II 


14 


18 


21 


25 


28 


32 


i8 


13 


18 


22 


27 


31 


36 


40 


20 


17 


22 


27 


Z2> 


38 


44 


50 


22 


20 


27 


33 


40 


47 


54 


60 


24 


24 


32 


40 


47 


55 


64 


71 


26 


28 


37 


46 


S^ 


64 


75 


84 


28 


32 


43 


53 


65 


75 


86 


97 


30 


2>7 


50 


62 


74 


^7 


100 


112 


32 


42 


56 


70 


84 


99 


112 


127 


34 


48 


64 


79 


96 


III 


128 


143 


36 


54 


71 


89 


108 


125 


142 


161 


38 


60 


79 


99 


120 


139 


158 


179 


40 


66 


88 


no 


132 


154 


176 


198 


42 


73 


97 


121 


146 


170 


194 


220 


44 


80 


107 


nz 


160 


187 


214 


-40 


46 


88 


117 


HS 


.76 


204 


234 


^62 


48 


95 


127 


158 


190 


222 


254 


286 


50 


103 


138 


172 


206 


241 


276 


310 


52 


112 


149 


186 


224 


260 


298 


335 


54 


121 


160 


200 


242 


281 


320 


362 


5^ 


130 


172 


214 


260 


302 


344 


389 


58 


139 


1^5 


231 


278 


324 


370 


417 


60 


149 


198 


247 


298 


336 


396 


446 



HOW TO CALCULATE THE CAPACITY OF 
TANKS. 

In circi^ar tanks, every foot of depth, five feet diameter, 
^ves 4^ barrels of 31^ gallons each; six feet diameter, 6^ 
►arrels ; seven feet diameter, 9 barrels ; eight feet diameter, 
2 barrels; nine feet diameter, 15 barrels; ten feet diameter, 
83^ barrels. In the case of square tanks, for every foot of 
epth 5 feet by 5 feet gives 6 barrels; 6 by 6 feet, 8^1^ bar- 
ils; 7 by 7 feet, 11)4, barrels; 8 by 8 feet, 15^ barrels ; 9 
y Q feet, I9J^ barrels: 10 hy lo feet, 23^4^ barrels. 



336 

NUMBER OF BOILER RIVETS IN A loo POUND 

KEG. 



Length. 


^2 


9-16 


% 


11-16 


% 


^ 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 


Inch. 




990 


760 


56'^ 


450 






\ys 


875 


725 


530 


415 






iX 


800 


690 


490 


389 


356 


228 


1/8 


760 


650 


460 


370 


329 


211 


l}j 


730 


625 


425 


357 


290 


180 


i/s 


710 


595 


505 


340 


271 


174 


I'X 


690 


550 


390 


325 


264 


169 


Iji 


665 


530 


375 


312 


257 


165 


2 


630 


510 


360 


297 


248 


156 


2y8 


590 


500 


354 


289 


237 


152 


2X 


555 


490 


347 


280 


232 


149 


2% 


525 


475 


ZZS 


260 


219 


141 


2% 


500 


440 


312 


242 


211 


133 


3 


460 


AIO 


290 


224 


203 


127 


3X 


430 


380 


267 


212 


190 


115 


3X 


410 


350 


248 


201 


180 


108 


3^ 


395 


335 


241 


192 


162 


102 


4 




326 


230 


184 ' 


158 


99 


4X 




312 


220 


177 


150 


96 


A}2 




298 


210 


171 


146 


94 


aYa 




284 


200 


166 


138 


!^ 


5 




270 


190 


161 


135 


^1 


5X 




256 


180 


156 


130 


84 


5^, 




244 


172 


151 


124 


80 


5?^ 




233 


164 


145 


120 


n 


6 




223 


157 


140 


115 


74 


6X 




213 


150 


137 


III 


71 


6 




207 


146 


134 


107 . 


69 


6 




203 


143 


129 


104 


67 


7 




n8 


140 


125 


100 


64 



To Bronze Iron Castings. — After havmg thoroughly 
cleaned the castings, immerse them in a solution of sulphate 
.A Lopper. The castings will then take on a coa<-ing of cop- 
•p'-r Then wash thoroughly in water. 



Copper is said to lose 18 per cent, of its tenacity upoi 
Deing raised f r om 60^ to 360*^- 



337 



NUMBER OF "AMERICAN" NAILS AND CUT 
SPIKES IN A POUND. 



•l-H _• 




G 








bi) 


i 


gth 
ches 









W) 




.S2 


a^ 


fl « 


OJ 


C 


*w5 


X 


(—1 


.,_, 


53 1— < 


N 





<u 


cS 





s 


:3 


^ 


C^ 


U 


^rl. 


u 


p; 


pJH 


U 


I 


2 F 


1050 










- ... -• 


i>^ 


3 F 


860 












1 


2 


900 












iJ4 


3 


500 




650 




670 




iX 


4 


300 




480 


450 


500 




^H 


5 


212 




350 


300 


370 




2 


6 


160 


85 


240 


212 


260 




2H 


7 


135 


65 


190 


160 


210 




2% 


8 


95 


50 


135 


120 


155 




2U 


9 


75 


40 










3 


lO 


60 


35 


115 


100 


135 


i6 


3X 


12 


48 


30 


100 




120 




3/^ 


i6 


34 


25 


80 




100 


14 


4 , 


20 


24 


20 


65 




85 


12 


4>^ 


30 


18 




50 




70 


10 


5 


40 


15 




40 




60 


9 


5X 


50 


12 










8 


6 


60 


10 










6 


7 














4;^ 


8 














4 



Clinch-nails weigh about the same as common. 

Box-nails are made ^ inch shorter than common nails of 
same sizes. 

5 lbs. of 4d or 3^ lbs. of 3d will lay 1,000 shingles. 5^ 
lbs. of 3d fine will put on 1,000 laths, four nails to the lath. 

Bricks made from the refuse of slate quarries arc stronger 
than stone; they stand 7,200 lbs. compression against 6,000 
for stone, and 3,200 lbs. for common brick. The cost is from 
$12 to $20 per thousand. 

In London 20,000 men earn their living at carpenter work* 
4,000 in Paris, and 4,000 in Berhn. Hours in London are 

52 j^ per week. 



338 
WAXING FLOORS. 
Take a pound of the best beeswax, cut it up into very small 
pieces, and let it thoroughly dissolve in three pints of turpen- 
tine, stirring occasionally if necessary. The mixture should 
be only a trifle thicker than the clear turpentine. Apply it 
with z. rag to the surface of the floor, which should be smooth 

and perfectly clean. This is the difficult part of the work, 
forj if you put on either too much or too little, a good polish 
will be impossible. The right amount varies, less being 
required for hard, close-grained wood, and more if the wood 
is soft and open-grained. Even professional " waxers " are 
sometimes obliged to experiment, and novices should always 
try a square foot or two first. Put on what you think will be 
enough, and leave the place untouched and unstepped on for 
twenty-four hours, or longer if needful. When it is thor- 
oughly dry, rub it with a hard brush until it shines. ^ If it 
polishes well, repeat the process over the entire floor, vj. If it 
does not, remove the wax with fine sandpaper and try again, 
using more or less than before, as may be necessary, and con- 
tinuing your experimenting until you secure the desired result. 
If the mixture is slow in drying, add a little of any of the 
common " dryers" sold by paint dealers, japan for instance, 
in the proportion of one part of the drier to six parts of tur- 
pentine. )When the floor is a large one, you may agreeably 
vary the tedious work of polishing by strapping a brush to 
each foot and skating over it. 

HOW TO MAKE AN IVORY GLOSS ON WOOD. 
A most attractive ivory gloss is now imparted to wood 
surfaces by means of a simple process with varnish, the latter 
being of two kinds, namely, one a solution of colorless resin 
in turpentine, the other in alcohol. P^or the first, the purest 
copal is taken, while for the second sixteen parts of sandarac 
are dissolved in sufficient strong alcohol, to which are added 
three parts of camphor, and finally, when all these are dis- 
solved, they are combined with hve parts of well-shaken 
Venice turpentine. In order to insure the color remaining 
a pure white, particular care is essential that the oil be not 
mixed with the white paint previously put on. The best 
French zinc paint, mixed with turpentine, is employed, and, 
when dry, this is rubbed down with sandpaper, following 
which the varnish described is applied. 



CARE OF OAK LUMBER. 

Throughout the civilized world, except in extremely hot 
countries, one or more species of the oak is found. In this 
country oak forests abound in almost all the Southern and 
Central States. In species there are so many that even 
experienced lumbermen are frequently perplexed to correctly 
designate to which class a samp'e piece of wood belongs. 
Ordinarily in the yard trade but two kinds are known- 
white and red. Among shipbuilders, carriage-makers and 
machinists may be found live oak, a species of wood that is 
peculiarly adapted to purposes where immense strength is 
necessary. The average lumberman, when he talkb about 
white oak or red oak, is influenced solely by the color of the 
wood when it becomes partially seasoned. Again and again 
veterans in the wood-working business have been known to 
select red oak for white, and vice vej-sa in fact, from a 
dozen specimens of six different species of oak, they have 
been unable to correctly name a single sample. 

Oak is a wood* which calls for unusual and unceasing 
care ,in its manufacture. The tendency of oak, from the 
moment an ax is planted in the side of the tree, is to split, 
crack, and play all sorts of mean tricks on the owner. Such 
tendencies can be held in hand, and almost absolutely 
■)bviatecl, by following certain rules. A thick coat of water- 
:)ioof paint applied to the ends of the logs is a wise expendi- 
ure ; it prevents the absorption of moisture. Oak, when 
piled, should have the ends protected so as to prevent absorp 
tion of rain and moisture, followed by the baking process of 
a hot sun Alternate moisture and heat is the prime cause 
of checks and cracks, and when such defects begui in oak 
they are bound to increase and ruin otherwise perfect stock. 

Oak should be stuck as fast as sawed. It is a mistake to 
permit it to lie in a dead pile even for a single day. Jt is a 
wood that contains a large amount of acitl, which oozes to the 
surface as fast as the lumber is sawed, and, if the stock i.s 
allowed to remain piled solid, it is apt, evcu in a few hours, 
to cause stain on the surface. The lumber should be stuck 
in piles not over six feet in width.* The bottom course 
should be raised two feet from the ground, and a space of five 
inches left between tlie pieces. It is advisable to follow this 
rule up to about t?:^ nfth course, when tne space can be 
gradually diminished to two inches, and continued to the top 
>f the pile. In this v/ay air has free circulation through the 
le, and the lumber will dry readily. The pde should ca«H 
ward the back, so that rain will fallow the iiclination. 



;4^ 

Board sticks not over three inches wide should be used, 
the front stick placed so as to project a half inch beyond the 
lumber. This plan permits moisture to gather in the stick, 
not the lumber. Other sticks should be placed not over foui 
feet apart, and in building the pile the sticks should be 
exactly over one another. By this plan, warps, twists and 
sags are avoided. 

It is advisable to pile every length by itself. This rule 
permits more systematic piling, and, in shipping, consign- 
ments can be made of lengths precisely as wanted. Thick- 
nesses in piling should never be mixed. Twisted stock is 
certain to be the result if this advice is ignored. 

The sap should be placed downward. The draft is up- 
ward, and any practical lumberman can readily observe the 
advantage of this advice. Every pile should be well covered 
^ith sound culls, the covering so placed as to project beyond 
all sides of the pile. Raise it a foot from the top course. 
The piles should not be nearer than twenty inches^apart; 
twenty-four inches is better. 

HOW TO SHARPEN A PLANE-IRON. 

The simple art of sharpening a plane-iron is supposed to 

De understood by every mechanic, remarks a writer in a 

contemporary, but there are hundreds of men who cannot do 
a creditable job in this respect. The common tendency is to 
round off the edge of the tool until it gets so stunted that 
under a part of the cutting the tool strikes the work back of 
the cutting edge. To do the job correctly we will begin at 
the beginning, and grind the tool properly. First, the kind 
of wood to be cut must be taken into consideration. Com- 
mon white pine can best be worked with a very thin tool, 
ground down even to an angle of 30 degrees, provided the 
make of the tool will allow it. Some planes will not, for the 
iron stands so " stunt," or nearly perpendicular, that its grind- 
ing causes a severe scraping action, which soon wears away the 
tool. In such cases, from 45 to 60 degrees is the proper 
angle for plane-iro»% and this, too, is about right for hard- 
wood planing. < 

Determine the angle you want on the plane-iron and thea 
grind to that angle, taking care to grind one flat bevel, and 
not work up a dozen facets. If the stone be small, say 12 to 
18 inches in diameter, the bevel will be slightly concave 
like the side of a razor, and this is a quality highly prized by 
many good workmen. In grinding, take care to avoid a 
"feather edge." If the tool aheady possesses the ri^t 



^rilape, grind carefully right up to thi? edge, but not grinding 
it entirely off. The time to stop grinding a tool is just before 
the old bevel is ground off. 

Should the tool need any change of shape, such as the 
grinding out of a nick or a broken place, then put the edge 
of the tool against the stone and bring the tool to the de- 
sired shap^ before touching the bevel. 

Let the iron lay perfectly flat upon the stone, with a 
tendency only to bear harder upon the edge of the bevel 
than U'^on the heel. Move the iron back and forth on the 
stone as fast as your skill will allow, taking care that the 
heel of the bevel is not lifted from the stone. As you be- 
come proficient in whetting an iron, the heel may be lifted 
from the stone about the thickness of a sheet of paper, or 
just enough to prevent it from touching. The reason why 
many carpenters cannot set an edge is because they raise 
their hand too much, and perhaps rock the tool, thus forming 
a rounding bevel, the sure mark of a poor edge-setter. 

The proper way to oil-stone a tool is to continue the 
grinding by rubbing on the oil-stone until the bevel left by 
the grindstone is entirely moved and the edge keen and 
sharp. If this be properly done the tool need not be touched 
upon its face to the stone, but among a dozen good edge- 
setters not more than one can do it. It is a delicate opera- 
tion, and can only be acquired by long practice. Nine times 
out of ten the average workman is obliged to turn the plane- 
iron over and wet the face thereof, and here is where many 
men fail who have done the other things well. By raising the 
back of the tool only a very little the edge is "dubbed off," 
and regrinding of the face becomes an immediate necessity. 
A good stone should " set " an edge on a tool wh» jh will shave 
off the hair on a person's wrist without cutting the skin ci 
missing a single hair. 

VALUE OF MAHOGANY, 

As is known to every woodworker, mahogany has nc 

flqnalfor durability, brilliancy, and intrinsic value for any 

work which requires nicety of detail and elegance of finish. 
Cherry, which is a pretty wood for effect, and extremely 
pleasing when first finished, soon grows dull and grimy- 
looking. Oak, which has been so much used of late, is 
attractive when first finished, but experience teaches that it 
does not take many months to change all this, and instead of 
i^ light, fresh looking interior, one tliat has a dusty appear- 
•^JOiC^ is presented, which no amount of scraping and re- 



34^ 

caking will restore to its original beauty. What applies lo 
in this yet more applicable to ash. 

Mahogany, however, seems to thrive best under the condi- 
tions which are detrimental to these other woods. At first 
of a light tone, it grows deeper and more beautiful m color 
with age, and although its first cost is more than these other 
woods, yet its price is much less than is popularly supposed ; 
and the only objection urged against it has been cost. What 
is more valuable, however, and what makes mahogany in 
reahty a less costly wood, is the fact that, unlike cherry, oak 
or ash, it is easily cleaned, because it is impervious to dust or 
dirt, while it does not show wear, and instead of growing 
duller, grows brighter and more pleasing in appearance. 
While first cost is more than that of cherry, oak or ash, it is 
nevertheless true that the judgment of many men has led 
them to regard mahogany as the cheaper wood when its dura- 
bility and cleanly qualities are considered, and to-day it takes 
|bnt rank in first-class material. 

POLISHING GRANITE. 

The form is given to the stone by the hands of skilled 

masons in much the same way as is done with other stone of 

softer nature. Of course, the time required is considerably 
preater in the case of granite as compared with other stones. 
If the surface is not to be polished, but only fine-axed, as it 
IS called, that is done by the use of a hammer composed of a 
number of slips of steel of about a sixteenth of an inch thick, 
which are tightly bound together, the edges being placed on 
the same plane. With this tool the workman smooths the 
surface of the stone by a series of taps or blows given at a 
right angle to the surface operated upon. By this means 
the marks of the blows as given obliquely on the surface of 
the stone are obliterated, and a smooth face produced. 
Polishing is performed by rubbing, in the first place, with 
an iron tool and with sand and water. Emery is next 
applied, then putty with flannel. All plain surface and 
molding can be done by machinery, but all carvings, or sur- 
faces broken into small portions of various elevations, are 
done by the hands of the patient hand-polishers. 

The operation of sawing a block of granite into slabs tor 
panels, tables or chimney-pieces is a very slow process, the 
late of progress being about half an inch per day of ten hours. 
The machines employed are few and simple; they are tech- 
nically called lathes, wagons and pendulums or rubbers. The 
lathes are employed for the polishing of columns, the wagons 



343 

for flat surfaces, and the pendulums for molding and such flat 
work as is not suitable for the wagon. In the lathe the 
column is placed and supported at each end by points upon 
which it revolves. On the upper surface of the column there 
are laid pieces of iron segments of the circumference of the 
column. The weight of these pieces of iron lying upon the 
column, and the constant supply of the lathe-attendant of 
sand and water, emery or putty, according to the state of 
finish to which the column has been brought, constitute the 
whole operation. While sand is used during the rougher 
state of the process these irons are bare, but when using emery 
and putty, the surface of the iron next to the stone is covered 
with thick flannel. 

The wagon is a carriage running upon rails, in which the 
pieces of stone to be polished are fixed, having uppermost the 
surface to be operated upon. Above this surface there are 
shafts placed perpendicularly, on the lower end of which are 
fixed rings of iron. These rings rest upon the stone, and 
, -when the shaft revolves they rub the surface of the stone. At 
the same time the wagon travels backward and forward 
upon the rails, so as to expose the whole surface of the stone 
to the action of the rings. The pendulum is a frame hung 
upon hinges from the roof of the workshop. To this frame 
are attached iron rods, moving in a Horizontal direction. In 
the line upon which these rods move, and under them, the 
stone is firmly placed upon the floor. Pieces of iron are then 
loosely attached to the rods, and allowed to rest upon the sur- 
face of the stone. When the wdiole is set in motion, these 
irons are dragged backward and forward over the surface of 
the stone, and so it is polished. When polishing plain sur- 
faces, such as the needle of an obelisk, the pieces of iron are 
flat ; but when we have to polish a molding, we make an 
extra pattern of its form, an«d the irons are cast from that 
pattern. 

IN FAVOR OF SMALL TIMBER. 

The statement that a 12x12 inch beam, built up of 2x12 
planks spiked together, is stronger than a 12x12 inch solid tim- 
ber, will strike anovice as exceedingly absurd. An authority 
on the subject says every millwright and carpenter knows that it 
is so, whether he ever tested it by actual experience or not. 
The inexperienced will fail to see why a timber will be 
stronger simply because the adjacent vertical longitudinal 
portions of the wood have been separated by a saw, and if 
this were the only thing about it, it would not be stronger. 



344 

but the old principle that a chain is no stionger that its 
weakest link comes into consideration. Most timbers have 
knots in them, or are sawed at an angle to the grain, so that 
they will split diagonally under a comparatively light load. 
In a built-up timber no large knots can weaken the beam 
except so much of it as is compc3ed of one plank, and planks 
whose grain runs diagonally will be strengthened by the 
other pieces spiked to them. 

VALUABLE ARTESIAN WELLS. 

Two artesian wells recently sunk in Sonoma Valley, 
Cal., are considered to be worth not less than $10,000 each. 
One of them flows 90,000 gallons of water per day, and the 
other 100,000. 



The cement by which many stone buildings in Paris have 
been renovated is likely to prove useful in preparing the 
foundations for machinery. The powder which forms the 
basis of the cement is composed of two parts of oxide of 
zinc, two of crushed limestone and one of pulverized grit, 
together with a certain proportion of ochre, as a coloring 
agent. The liquid with which this powder is to be mixed 
consists of a saturated solution of six parts of zinc in com- 
mercial muriatic acid, to which is added one part of sal-ammo- 
niac. This solution is diluted with two-thirds of its volume 
of water. A rnixture of one pound of the powder to two 
and a half pints of the liquid forms a cement which hardens 
quickly, and is of great strength. 

Large cylinders of window-glass are now cut by encircling 
the cylinder with a fine wire, which is then heated to redness 
by an electric current, and a drop of water being allowed to 
fall upon the hot glass a perfectly clean cut is obtained. 
The old method was to draw out a fiber of white-hot semi- 
molten glass from the furnace by means of tongs, and to 
wrap it round the cylinder. 

The Hudson Bay Company, which was incorporated 225 
years ago, is the oldest incorporated company. 

The grindstone quarries along the shores of the Bay of 
Fundy are developed when the tide is down. The best ma- 
terial is down low in the bay. 

Some fine pearls were recently discovered in Tyrone (Ire- 
land) rivei'S. 



345 



\A^OODEN BEAMS. 

Safe Load. Uniformly Distributed, for Rectan* 
gular White or Yellow Pine Beams one inctl 
thick, 

allowing 1,200 lbs. per square inch fibre strain. 

To obtain the safe load for any thickness, multiply the 
safe load given in table by the thickness of beam. 

To obtain the required thickness for any load, divide 
by the safe load for i inch given in table. 



If 


DEPTH OF BEAM. 


6" 
Lbs. 


7" 1 8" 


0" 

Lbe. 


10^' 

Lbs. 


11" 

Lbs. 


12"! 13'' 


14// 


15" 


16" 


r«6t 


Lb^ 


Lbs. 


Lbs. 


lbs. 


Lbs. 


Lbs. 


■Lbs. 


^ 


960 


1310 


1710 


2160 


2670 


3230 


3840 


4510 


5230 6000 


6830 


6 


800 


1090 


1420 


1800 


2220 


2690 


8200 


3760 


4360 5000 


5690 


7 


690 


930 


1220 


1540 


1900 


2300 


2740 


3220 


8730 


4290 


4880 


8 


600 


820 


1070 


1350 


1670 


2020 


2400 


2820 


3270 


8750 


4270 


9 


530 


720 


950 


1200 


1480 


1790 


2130 


2500 


2900 


3330 


3790 


10 


480 


650 


850 


1080 


1330 


1610 


1920 


2250 


2610 


zm 


3410 


11 


440 


590 


780 


980 


1210 


1470 


1750 


2050 


2380 


2730 


3100 


12 


400 


540 


710 


900 


1110 


1340 


1600 18S0 


2180 


2500 


2840 


13 


370 


500 


660 


8^0 


1030 


1240 


1480 1 1730 


£010 


2310 


2630 


14 


340 


470 


610 


m 


950 1150 


1370 • 1610 


1870 


2140 


2440 


16 


320 


440 


570 


720 


890 rd80 


1280 ! 1500 


1740 


2000 


22S0 


16 


300 


410 


530 


680 


830 


1010 


1200 1410 


1630 


1880 


2130 


17 


280 


880 


500 


640 


780 


950 


1130 1330 


1540 


1760 


2010 


18 


270 


860 


470 


600 


740 


900 


1070 11250 


1450 


1670 


1900 


19 


250 


340 


450 


570 


700 


850 


1010 


1190 


1380 


1680 


1800 


20 


240 


830 


430 


540 


670 


810 


960 


1130 


1310 


1500 


1710 


21 


230 


.310 


410 


510 


630 


770 


910 


1070 


1240 


1430 


1630 


22 


220 


300 


390 


490 


610 


730 


870 


1020 


1190 


1360 


1550 


23 


210 


280 


370 


470 


580 


700 


830 


980 


1140 


1300 


1480 


24 


200, 


.^70 


360 


450 


560 


670 


800 


940 


1090 


1250 
^200 


1420 


25 


190 


260 


340 


430 


530 


650 


770 


900 


1050 


1370 


26 


180 


260 


830 


420 


510 


620 


740 


870 


1010 


1150 


1310 


27 


180 


240 


320 


400 


500 


600 


710 


830 


970 


1110 


1260 


28 


170 


230 


800 


890 


480- 


680 


690 


800 


930 


1070 


1220 


29 


170 


230 


290 


870 


460 


660 


660 


780 


900 


1030 


1180 



34^ 

WEIGHT OF 
A CUBIC FOOT OF SUBSTANCE. 



Average 

Names of- Substances. 'Weight. 

■ Its. 

Anthracite) solid, of Pennsylvania, - - * - 93 

" broken, loose, - - . - # 54 

*• • *• moderately shaken, - . - 58 

** heaped bushel, loose, . - - ^ (80) 

Ash, American white, dry, --» * ^ - 38 

Asphaltum, ....*-,•- 87 

Brass, (Copper and Zinc,) castt * « • * • 604 

« rolled, - - - .' • *^ " - 624 

Brick, best pressed,^ - - • •? -» -s - 160 

*' common hard, - - - * • •» 126 

*' soft, inferior, .---..- 100 

Brickwork, pressed brick, - - • - ' 140 

ordinary, - - - - ^ -' : - 112 

Cement, hydraulic, ground, loose, American, Rosendale, 66 

*l « " . " ** Louisville, 60 

•* " « " English, Portland, - 90 

Qherry, dry, * -- - -x- -^^42 

Chestnut, dry, - . - - - - - .- » 41 

Coal, bituminous, solid, - 7 - * - - 84 

" " broken, loose, ^ - % - * .49 

" ** heaped bushel, loose, ^- - - (74) 

Coke, loose, of good coal, - .'- ■? -. * 27 

'• ** heaped bushel, -■, - * / * " * (SSj 

Copper, cast, - ^ - . , - ,^ ^ - , * 642 

rolled, . - .. - ^ • 543 

Earth, common loam, dry, loose, - - • "^ * 76 

*' " " *' moderately rammed, 95 

" as a soft flowing mud, - ' * • 108 

^bony, dry,» .*•.♦« 76 

Eim, dry, • * ^ * •, • • 35 

Flint, -^ -- - . ^ «' 162 

Glas!;, common window^ *j ^ w ' 157i 



347 
WEIGHT OF SUBSTANCE. 

(CONTINUED.) 



Names of Substances. . wei.gbt 

Lba 

Gneiss, common, - 168 

Gold, cast, pure, or 24 carar. 1204 

" pure, hammered, . « . - . -1217 

Granite, 170 

Gravel, about the same as sand, which see. 

Hemlock, dry, . . - • - • • - 25 

Hickory, dry, - . ^ 53 

Hornblende, black, - . - . - , - 203 

Ice. , - . - 58.7 

(ron, cast. - - - 450 

" wrought, purest, - . - - - - 485 

" " average, - - - - - - 480 

Ivory. 114 

Lead, . - - 711 

Lignum Vitae, dry, .--.--- 83 

Lime, quick, ground, loose, or in small lumps, - «• 53 

" " " thoroughly shaken, - - 75 

" " •• " per struck bushel, - - (66! 

Limestones and Marbles, ------ 108 

" " loose^ in irregular fragments, - 96 

Mahogany, Spanish, dry, - - - - - '' 53 

Honduras, dry, - - . - - - 35 

Maple, dry, •- 49 

Marbles, see Limestones. 

Masonry, of granite or limestone, well dressed, - 165 

•' mortar rubble, ----•. 154 

" dry •• (well scabbled,) - * 138 

" sandstone, well dressed, .... I44 

Mercury, at 32° Fahrenheit, - . , ► . 849 

Mica, 183 

Morlar, hardened, •<..... 103 

Mud, dry, close. - 80 to 110 

" wet, fluid, maximum, --...- 120 

Oak, live, dry, - - - ^ , • - , ♦ 59 



348 
WEIGHT OF SUBSTANCES. 

(CONTINUED.) 

Names of Substances. Weight 

Lte. 
Oak, white, dry, -----.. 52 

*♦ other kinds,- 32 to 45 

Petroleum, ---.--.-- ,55 

Fine, white, dry, --.-..-25 

" yellow. Northern, -...-. 34 

** " Southern, - - . . . - 45 

Platinum, - -- - - • . - 1342 
Quartz, common, pure, ---.-.. I65 

Rosin, --_---. .-69 
Salt, coarse, Syracuse, N. Y- ... . - - 45 

" Liverpool, fine, for table use,\ - - - i. 49 

Sand, of pure quartz, dry, loose, - - - 90 to 106 

'* well shaken, 99 to 117 

*' perfectly wet, ----- 120 to 140 
Sandstones, fit for building, - - - - - 15X 

Shales, red jor black, '-.---. 102 

Silver, --- 655 

Slate, - . . - ." - . - - 175 

Snow, freshly fallen, - - - - ^ 6 to 12 

" moistened and compacted by rain, - - 15 to 50 
Spruce, dry, -^- - - > - -- 25 
Steel. -------..- 490 

Sulphur, -,- -- - ^ - . 125 

Sycamore, dry, - - - -- - ^ -, 37 

Tar, - - - _ - - - ... 62 

Tm, cast, -^* - ^ - 459 

Turf or Peai, dry, unpressed, - - - - 20 to 30 

Walnut, black, dry, - - - - - - .- 33 

Water, pure rain or distilled, at 60° Fahrenheit, - 62>^ 

'• sea, -- r. - - - - -64 
Wax, bees, - - ,. - . . . . 60.5 
Zinc or Spelter, '--- 437 

Green timbers usually weigh from one-fifth to one-half more 
than dry. 



349 



ROUND CAST IRON COLUMNS.—Safe Load in Tons of 2,000 
pounds ; safety, 6. — These tables are based on columns made 
of the best iron, perfectly molded and with both ends turned. 



« * 



Oltisill 


B Diameter, 3 in. 


J^in. 


5iin. 


lin. 


44,070 


69,890 


71,190 


»H,»94 


53,535 


63,636 


34,579 


46,992 


55,859 


«0,i!31 


41,083 


48,835 


26,26S 


35,698 


42.433 


22,812 


31,001 


36,851 


19,844 


26,967 


32,056 


17,339 


23,564 


28.010 


15,147 


20,694 


24,630 


13,402 


18,213 


21,650 


11,785 


16,123 


19,223 


10,469 


14,335 


17,097 


9,453 


12,84 7 


15,271 


Ontsidf 


) Diameter 


r, 6 in. 


J^in. 


Uin. 


lin. 


' 79,100 


141,250 


113,000 


74,118 


132,353 


105,833 


68,99« 


123,207 


98,566 


63,886 


114,082 


91,266 


68,951 


105,270 


84,216 


64,261 


96,895 


7 7,516 


49,875 


89,062 


71,250 


45,826 


81,832 


65,466 


42,105 


7 5,187 


60,150 


88,710 


69.125 


55,300 


85,618 


63,603 


50,833 


32,830 


58,625 


46,900 


30,298 


54.I(K{ 


43,283 


28,003 


50,006 


40,005 


25,931 


46,306 


37,04 5 


24,056 


42,957 


34,366 


Ontsid 


B Diamete 


r, 7 in. 


5i in. 


lin. 


V4 in. 


166,110 


212,440 


255,380 


158,664 


202.917 


24 3.933 


151,086 


193,226 


232,282 


143,283 


183,37 5 


220,4 40 


135,769 


17 3,636 


208,783 


128,198 


163.954 


197,094 


120,936 


154,667 


185.930 


113,948 


145,730 


175,186 


107,824 


137,258 


165.002 


101,062 


129,250 


1 55,3 7 5 


95,123 


121,654 


146,24 4 


89,567 


114,548 


137,701 


84,27 5 


107,780 


129,565 


79,380 


101,520 


122.040 


74,798 


96,660 


114,995 


70,589 


.90,27 7 


108,525 


66,635 


85,220 


1(^2,458 


02,930 


80.4 82 


W6,750 



6 
7 
8 
9 
10 
11 
12 
13 
14 
1 5 
16 
17 
18 
19 
20 
21 
22 
23 



8 
9 
10 
11 
12 
18 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
2.^ 



Outside Diameter, i in. 



l^ in: 

61,02(H 
56,140 
51,246 
46,552 
41,858 
37,912 
33,885 
30,701 
27,476 
25.000 
22.464 
20,511 
18,557 



U in. 


1 in. 


85,880 


106,220 


79.202 


98,020 


7 2,124 


89,206 


65,968 


82,035 


58,912 


7 2,865 


53,303 


65,925 


4 7,690 


58,985 


42,681 


53,011 


3S,K7 1 


4 7,830 


34,794 


43.167 


31.616 


39,104 


28,567 


;{5,504 


26,1 !8 


32,304 



Outside Diameter,^ in. 



2£in. 


lin. 


140,120 


177,410 


132,782 


168,120 


125,253 


158,587 


117,676 


148,993 


109,945 


139,205 


103,021 


130.438 


96,119 


121,700 


89,612 


1 13,448 


83,514 


105.7 39 


77,810 


98,517 


72,532 


91,835 


67,633 


85.632 


63,094 


79,886 


58,962 


7 4,653 


55.131 


69,803 


51,684 


65,312 


48,348 


61,21 5 


45,365 


57,4 38 



V4 in. 

210,180 

199,174 

187.880 

176,514 

164.908 

154.532 

144,179 

134.403 

125,271 

1 l(>.715 

IOS,79S 

101.449 

94.(142 

88.443 

82,69 7 

77,376 

7 2,523 

68.048 



Outside Diameter, 8 in. 



K in. 

193,230 
185,6 71 
177,942 
170,110 
162,279 
154,359 
146,700 
139,655 
132,552 
125,787 
119.323 
1 13,15(» 
107.3(^2 
101,796 

96,580 
-91.656 
/87.009 

82.695 



I in. 

248,600 
238,876 
228.t»32 
218,856 
208,780 
198,(;38 
188,738 
179.674 
170,535 
161.832 
153.516 
145,574 
138.050 
130,966 
124.25<J 

I 17.920 

II 1.94 2 
106.31>2 



/4 



in. 



299,450 
287,73 7 
2 7 5,759 
263.622 
251.485 
2 3 '.1.2 6 S 
227.343 
2I(>.42.. 
205.4 17 
194,U34 
1S4.9i: 
17 5,350 
166,487 
15 7.754 
14 9.672 
14 2.040 
I34.s:{'» 
I2s.l.i» 



350 



BOUND CAST IRON COLUMNS — (Continued). 



i 


Oatside Diaftieter, 16 in. 


t 

a 
•9' 


OnUide Diameter, 16 in. 


5 


liD 


ly^in. 


,;2in., 


134 m. 


2 in. 


2)6 in. 


)15 


496,974 


718,793 


922.584 


16 


772,129 


9ft3,648il,198,139 


IIS 


486,727 


703,97 2 


903,958 


17 


757.143 


974,78511,175,918 


17 


476,259 


688,833 


884.513 


18 


741,996 


955.168 1,161,880 


18 


465,654 


673,666 


864.910 


19 


726,521 


985,897 1,127,623 


J% 


464,978 


658,045 


84 4.980 


20 


711,042 


916,3121,103,848 


20 


444,242 


642,625 


825,050 


21 


695,394 


895,149 


1.079,067 


21 


433,467 


626,940 


805.038 


22 


679,610 


874.750 


1,064,674 


22 


422,736 


611,419 


785.108 


23 


664,031 


854.795 


1,030,400 


23 


412,005 


695,898 


764,178 


24 


648,452 


834.740 


1,006.226 


24 


401,405 


680.568 


7 4 5,493 


25 


632.941 


814.778 


982,156 


25 


800,938 


565,429 


726,054 


26 


617,667 


7 94,982 


958.299 


26 


880,559 


550.417 


706,777 


27 


602,329 


775,867 


984,657 


27 


870,400 


635,733 


687,909 


28 


587,296 


756,016 


911,328 


2H 


360.240 


521,220 


669,286 


29 


572,637 


737,017 


888.366 


29 


850,565 


507,035 


651.071 


80 


557,983 
548,702 


718,281 


866,841 


SO 


840,933 


493.106 


633,183 


31 


699.918 


843,681 


«S1 


880.921 


479,492 


615,704 


32 


529.694 


681,866 822,34 6 
664,186^ 800,033 


82 


822.329 


466.198 


596,633 


33 
26 


516,960 




Outside Diameter, 17 in. 


Outside Diameter, 17 in. 




IHin. 
825,852 1 


2in: 


2Km. 


1)6 in. 
686.503 


2 in. 


2}i in. 


J'' 


,065.026 


1,286,84 4 


885,856 


1,070,368 


1h 


809,752 1 


,046,798 1.263,012 


27 


671,018 


865,876 


1,046,216 


iu 


795,333 1 


,026.l98|l,240.039 


28 


665,753 


846,176 


1.022,416 


20 


7 79,994 1 


.006,495 1.216,125 


29 


640,634 


826,667 


998,841 


21 


764,610 


986.515:1,101,982 


30 


626,661 


807,846 


976,496 


22 


748,952 


966.439,1.167.726 


31 


610.907 


788,807 


962,492 


28 


788,832 


946,27 9,1,1 43,355 


32 


596.4 55 


769,645 


929,944 


24 


717.618 


22<(,006|K1 18,871 


33 


582.132 


7 44,267 


907.787 


26 


702,060 


90a,98i;i.094,615 


84 


566.206 


730.626 


882.798 



NEW STEEL .RAILS USED AS LINTELS GR GIRDERS. 
6afc load in tons of 2000 lbs. 



=^ 



Length [ 2 



52 lb. rail, per yardjl0.7oj 7.00 



60 )b rail, ycr yard'l2. 



8.00 



5 65 4 75 
Deflection in inches'o.045|o O'lOO 07 5 0.090 



5.0O! 1.2. 



3.50 3. 



2.7- 



4.O0I 3 50, 8. 



125 170 



Dctlectioniu Inches 0.47 6^ 4 5u 



0.226 



2.60 



2.70 
OSOO 




536 O.Om'0. 7300.830 0.93a' 



j5i 
AREAS OF CIRCLES. 

Advancing by Eighths. 



AREAS. 



.0 

.7854 
3.141C 
7.068 
12.56 
19.63 

28.27 
38.48 
50.26 
63.61 
78.54 

95,03 
113,0 
132,7 
153.9 
176.7 

201.0 
226.9 
254.4 
283.5 
314.1 

« ] i 
346 3 
380.1 
415.4 
452.3 
490.8 

530.9 
572.5 
615.7 
660.5 
706,8 

754.8 
804,3 
8.55.3 
907. 9 
962.1 

1017.9 
1075.2 
1134.1 
1194.6 
1256. f-\ 

1320. A 
1385.1 
J452.2 
1520.5 
1590.4 



.0122 
.9940 
3.546 
7.669 
13.36 
20.62 

29.46 
39.87 
51.84 
65.39 
80.51 

97.20 
115.4 
135.2 
156.6 
179.6 

204 . 2 
230 3 

258.0 
287.2 
318.1 

350.4 
384.4 
420.0 
457 1 
495.7 

536.0 
577.8 
621.2 
666.2 
712.7 

760.9 
810.6 
861.8 
914.7 
969.0 

1025.0 
1082.5 
1141.6 
1202.3 
1264.5 

1328.3 
1393. 7 
1460.7 
1529.2 
1599.3 



.0490 
1.227 
3 . 976 
8.295 

14.18 

21.64 

30.67 
41.28 
53.45 
67.20 
82.51 

99.40 
117.8 
137.8 
159. i 
182.6 

207.3 
23 J. 7 
261.5 
291.0 
322.0 

354.6 

388.8 
424.5 
461.8 
500.7 

541.1 
583.2 
626.7 
671.9 
718.6 

767.0 
816.9 
868.3 
921.3 
975.9 

1032.1 
1089.8 
1149.1 
1210.0 
1272.4 

1336.4 
1402.0 
1469.1 
1537.9 
1608.2 



.1104 
1.484 
4.430 
8.946 
15.03 
22.69 

31.91 
42.7; 
55 . 08 
69 . 02 

84.54 

101 6 
120.2 
140.5 
162.2 
185.6 

210.5 
237.1 
265.1 
294.8 
326.0 

358.8 
393.2 
429. 1 
466. 6 
505. 7 

546.8 
588.5 
632.3 
677.7 
724.6 

773.1 
823.2 
874.9 
928.1 
982.8 

1039.2 
1097.1 
1156.6 
1217.7 
1280.3 

1344.5 
1410.3 
1477.6 
1546.6 
1617.0 



.1963 
1.767 
4.908 
9.621 
15.90 
23.75 

33.18 
44.17 
56.74 
70.^8 
86.59 

103.8 
122.7 
143.1 
165 1 
188.6 

213.8 
240.5 
268.8 
298.6 
330. 

363.0 
397 6 
433.7 
471.4 
510.7 

551.5 
593.9 
637.9 
683.4 
730.6 

779,3 
829.6 
881.4 
934.8 
989 8 

1046.3 
1104.5 
1164.2 
1225.4 
1288.2 



1352. 
1418. 
1486. 
1555. 



1626.0 



.3068 

2.073 

5.411 

10.32 

16.80 

24,85 

34.47 
45.66 
58.42 
72.75 
88.66 

106.1 
125,1 
145.8 
167.9 
191.7 

217.0 
243,9 
272:4 
302.4 
334.1 

367.2 
402.0 

438.3 
476.2 
515.7 

556.7 
599.3 
G43.5 
689.2 
736.6 

785.5 
836.0 
888.0 
941,6 
996,8 

1053.5 
1111,8 
1171,7 
1283.2 
1296.2 

1360.8 
1427.0 
1494,7 
1564.0 
1634 . 9 



'H 



.441; 
2,405 
5.939 
11,04 
17,72 
25.96 

85, 78 
47.17 
60. J3 
74.66 
90.76 

108.4 
127.6 
148.4 
170.8 
194.8 

220.3 
247.4 
276.1 
306.3 
338.1 

371.5 
406.4 
443.0 
481.1 
520.7 

562.0 
604.8 
649.1 
695.1 
742.6 

791.7 
842.4 
894.6 
948.4 
1003.8 

1 060. 7 

1119.2^ 

1179.3 

1241.0 

1304.2 

1369.0 
1435.4 
1503.3 
1572.8 
1643.9 



•% 



.6013 
2.7(il 
6.491 

11.79 

18.06 

27.10 

37,12 

48.70- 
61.86 
76 58 
92. 8« 



lie, 

130. 
151. 
173. 
19-7. 



223,6 
250.9 
279.8 

310.2 
342.2 

375.8 
410.9 
447.6 
485.9 
525.8 

567.2 
610,2 
654.8 
700.9 
748.6 

798.0 
848,8 
901.3 
955,3 
1010.8 

1068.0 
1126,7 
1186,9 
1248.8 
1312,3 

1377.2 
1443.8 
1511.9 
1581.6 
1652.9, 



352 
CIRCUMFERENCES OF CIRCLES. 

Advancing by Eighths. 









CIRCUMFERENCES 








CO 


' .0 


.^ 


■hi 


.H 


■M 


.56 


.H 


.T^ 


€ 


.0 


-3927 


.7854 


1.178 


1.570 


1.963 


2.356 


2.748 


1 


3.141 


3.534 


3.927 


4.319 


4.712 


5.105 


5.497 


5.890 


2 


6.283 


6.675 


7.068 


7.461 


7.854 


8.246 


8.639 


9.032 


8 


9.424 


9.817 


10.21 


10.60 


iO.99 


11.38 


11.78 


12. )7 


4 


12. 5*5 


12.95 


13.85 


13.74 


14.13 


14.52 


14.92 


15.31 


6 


15.70 


16.10 


16.49 


16.8.S 


17.27 


17.67 


18.06 


18.45 


6 


18.84 


19.24 


19.68 


20.02 


20.42 


20.81 


21.20 


•<? 1 . 59 


7 


21.99 


22.38 


22.77 


23.16 


28.56 


23.95 


24.. 34 


24 74 


8 


25.13 


25.52 


25.91 


26.31 


20.70 


27. oy 


•v»7.48 


27. S8 


9 


28.27 


28.66 


29.05 


29.45 


29.84 


80.23 


;!0.63 


31.(12 


10 


81.41 


81.80 


82.20 


32.59 


32.38 


33.37 • 


..33,77 


34.16 


11 


84.55 


84.95 


35.84> 


35.73 


86.12 


36.52 


36.91 


37.30. 


12 


3r.69 


38.09 


38.48 


38.87 


39.27 


39.66 


40.05 


40.44 


13 


40.84 


41.28 


41.62 


42.01 


42.41 


42.80 


43.19 


43.. 58 


14 


43.98 


44.37 


44.76 


45.16 


45.55 


45.94 


45.33 


46.73 


15 


47.12 


47.51 


47.90 


48.30 


48.69 


49.08 


49.48 


49.87- 


16 


50.26 


50.65 


51.05 


51.44 


51.83 


52.22 


52.62 


53.01 


17 


53.40 


53.79 


54.19 


54.58 


54.97 


55.37 


55.76 


56.15 


18 


56.54 


56.94 


57.33 


57.72 


58.11 


58.51 


58.90 


59.29 


19 


59.69 


60.08 


60.47 


60.86 


61.26 


61.65 


62.04 


62.43 


SO 


62.83 


63.22. 
66.80 ' 


68.61 


64.01 


64.40 


64.79^ 


65.18 


65.58' 


21 


65.97 


66.75 


67.15 


67.54 


67.93 


68.82 


68.72 


22 


69.11 


69.50 


69.90 


70.29 


70.68 


71.07 


71.47 


71.86 


23 


72.25 


72.64 


73.04 


73.43 


73.82 


74.22 


74.61 


75.00 


24 


75.39 


75.79 


76.18 


76.57 


76.96 


77.86 


77.75 


78.14 


25 


78.54 


78.93 


79.32 


79.71 


80.10 


80.50 


80.89 


81.28 


26 


81.68 


82.07 


82.46 


82.85 


83.25 


83.64 • 


84.03 


84.43 


27 


84.82 


85.21 


85.60 


86.00 


86.39 


86.78 


87.17 


87.57 


28 


87.96 


88.35 


88.75 


89.14 


89.53 


89.92 


90.82 


90.71 


29 


91.10 


91.49 


91.89 


92.28 


92.67 


93.06 


93.46 


93.85 


SO 


94.24 


94.64 


95.03 


95.42 


95.81 


96.21 


96.60 


96.99. 


81 


97.89 


97.78 


98.17 


98.57 


98.96 


99.35 


99.75 


100.14 


82 


100.53 


100.92 


101.32 


101.71 


102.10 


102.49 


102.89 


108.29 


88 


103.67 


104.07 


104.46 


104.85 


105.24 


105.64 


106.03 


106.42 


84 


106.81 


107.21 


107.60 


107.99 


108.89 


108.78 


109.17 


109.56 


85 


109.96 


110.35 


110.74 


111.18 


111.53 


111.92 


112.31 


112.7V 


86 


113.10 


113.49 


113.88 


114.28 


114.67 


115.06 


115 45 


lis. 85 


87 


116.24 


116.63 


117.02 


117.42 


117.81 


118.20 


118.61 


118.99 


88 


119.88 


119.77 


120.17 


120.56 


120.95 


121.34 


121.74 


122.13 


89 


122.52 


122.92 


123.31 


123.70 


124.09 


124.49 


124.88 


125.27 


40 


125.66 . 

i 


126.06. 


126.45 


126.84 



127.24 


127.63 


128-02 


128.41 


41 


128.81 


129.20 


127.59 


129.98 


130.88 


130.77 


[Si.f^^ 


m.70 


42 


181.<95 


132.34 


182.78 


133.13 


133.52 


133.91 


134.30 


43 


135.0ft . 
138.25. 


135.48 


135.87 


136.27 


136.66 


137.05 


137.45 


137.84' 


44 


138.62 


189.02 


139.41 


139.80 


140.19 


140.59 


140.98 


4*> 


141.87 


141.76 


142.16 


14?. 55 


142.94 


143.34 


143.73 


\M.y9 



353 

WEIGHT OF CAST IRON COLUMN PER LINEAL FOOT 
OF PLAIN SHAFT. 



2 
3 

4 

4H8 

6 
6)6 



I 

8 

9 

> 

10 

10'/^ 

11 

llj^ 

12 

12H 

13 
13»^ 

14 

15 
16 

i: 

18-. 

ly 

20 



THICKNESS OF METAL. 



'Ain. 



4.8 
55 



9.2 
10.4 

11.7 
12.9 

14.1 

15 3 

16 6 

17 8 

19 
20.2 

21 5 

22 7 

23 9 
25.2 

28 4 

27 6 

28 8 



%in, 



V^in. 



1 

18 91 24 5 



7 4 



12 3 
14 



17,2 
19.fi 



22 1 



8 4 9.2 
11 5 12 9 



27.8 
29 5 



31 9 



29.9 



39 1 



in. %in. lin 



16.6 
20.3 



23. 9j 
27.6 



31 3 
35 



38 7 
42 3 



46 



34 4 42 2 49 



36 8 45 
39 3; 4>^ 

41 7' 51 
44.2: fA 

46 61 51 
49 l! 60 



51 6 
54 8 



56 5 
58 9 



63 



53 4 



60 
'64 4 



14.71 

19 6 
24.6 



29.5 
34 4 



39 3 
44 2 



49 1 
54 



61 58 9 
9 63 8; 



IHin. 



V4in. 



'8 
71 81 82 



75 5 

79 2 



82.8 



72 9 88.5 

46 5' 61 4 75 9 90 2 
_.^ I 63 8 79 93 9 



3 82 

.7 85 



II 97 6 
2il01 2 



61 2 

65 5 



104 
108 



112 

117 



71 21 88 21104 9 121 
76 1 94 3112 3 129 



81 O'lOO 5ill9 7 
86 9)J06 6!l27 



90 81112 
95 7 118 



81134 4 
91141 'i 



155 
164. 



78 5 
83 5 



88 4 



93 3 


98 2 
103 1 


108 
112 9 


117 8 
122 7 


127 6 
132 5 


137 5 

147 3 


1.57 1 
166.9 


178 7 
186.5 



37.3 

42.6 
48^3 

53.9 
69. 4! 

64 9 

70.4 

75 9 
81.5 

87 oi 
92 51 

08 
103 5 

100 1 
114 6j 

120 1' 
126 6i 

131.21 

138 7 

142 2 
147 7 

153 2 

164 6 

175 3! 

186 i 

197 4' 
208 01 



39 9 



VAlD. 



46.0 



58.3 
64.4 



70.6 
76 7 



82.8 
89 



a5 1 

101 2 



107 4! 
113..ii 



no 

125 8 



131 9 
138 1 



144 2 

15(J 3 



156.5 
162 6 



168 
18) 01 



1V>3 3 

205 6 



217 8 
230 1 



l%in. 2 In 



81 -. 

88 4|.. 

95 7I . 
10» 1 



110.5 

ir 

125 2 
132 5 

139 9 
147 3 

1.5i:6 

162.0 



133. 2f. 



141 
150 



167 



176 
184 



71 1.^7 t 
3. 166 y 

9; 176 T 
5 J8C.5 

1! 196 3 
7; 20«i 2 



169 41 193 3: 216 
9i 225 8 



176 



184 1 
191 4 



198 8 
213 5 



238 3 
243 



t^l 7 
274 4 



201 



210 
219 



;V 2a5 6 
ll 245 4 



6 2.V) •* 



2tt? 
279 

296 
313 



274 VI 



'OH 5 
314 1 



IfWi 4 





Increase 


IN Weiubt foa 


'A »N 


Increase in Diameter 




«1D. 


J 8 


2.5 




3 7 


'/i in. 


1 in 
) 


I. '-8 in. ix.iin. 


1 
l>iin. U4ln 


2 in. 


>a 2 


4 9 


5^ 6 1 


7 4 8 6 


9.8 



354 

Weight of Square or Rectangular Cast Iron Col* 
umn Shafts Per Lineal Foot. 



Example : Column 6" X lo'' X i' 



6"X 



\o" ~ i6" X 2 = 32. Following out line on which 32 is 
found in left hand column to column headed i'\ we find 
the weight per foot to be 87.5 pounds, which, multiplied 
by 10' i" == 875 pounds. 

























A 




ivi e:ta L.. 




< 


1 1 




V 


lUh 


%•• 


2i" 


Vb!' 


1" 


irs" 


!%•■ 


\w 


IM" 


2" 


12 


18.6 
22.5 

26.4 


21.1 

25.8 
30.5 


23.3 

28.7 
84.2 


25.0 
31.3 
37.5 


26.4 
33.4 
40.4 


27.3 
35.1 
43.0 


28.1 
37.5 
46.9 






14 






16 


49.2 


60.0 


18 


30.3 


35.2 


39.7 


43.8 


47.4 


50.8 


66.3 


60.2 


62.5 


20 


34.2 


39.8 


45.1 


50.0 


64.6 


68.6 


65.6 


71.1 


76.0 


22 


38.1 


44.5 


60.6 


66.3 


61.6 


66.4 


75.0 


82.0 


87.5 


24 


42.0 


49.2 


56.1 


62.5 


68.6 


74.2 


84.4 


98.0 


100.0 


26 


45.9 


53.9 


61.6 


68.8 


75.6 


82.0 


93.8 


103.9 


112.5 


28 


49.8 


68.6 


67.0 


76.0 


82.6 


89.8 


103.7 


114.8 


125.0 


30 


53.7 


63.3 


72.5 


81.3 


89.6 


97.7 


112.6 


126.8 


187.6 


32 


57.6 


68.0 


77.9 


87.6 


96.7 


106.5 


121.9 


187.7 


160.0 


84 


61.5 


72.7 


83.4 


93.8 


103.7 


113.3 


131.3 


147.7 


162.5 


86 


65.4 


77.3 


88.9 


100.0 


110.7 


121.1 


140.6 


168.6 


176.0 


88 


69.8 


82.0 


94.3 


106.3 


117.8 


128.9 


150.0 


169.5, 


; 187.5 


40 


73.2 


86.7 


99.8 


112.6 


124.8 


186.7 


169.4 


180.6 


200.0 


42 


77.1 


91.4 


105.3 


118.8 


131.8 


144.6 


168.8 


191.4 


212.6 


44 


81.0 


96.1 


110.8 


125.0 


138.8 


162.3 


178.1 


202.3 


226.0 


46 


84.9 


100.8 


116.2 


131.3 


146.9 


160.2 


187.5 


213.3 


287.5 


48 


88.8 


105.5 


121.7 


137.6 


152.9 


168.0 


196.9 


224.2 


260.0 


60 


92.8 


110.2 


127.2 


148.8 


159.9 


175.8 


206.3 


235.2 


S62.6 


62 


96.7 


114.8 


132.6 


160.0 


167.0 


188.6 


215.6 


246.8 


276.0 


64 


100.6 


119.6 


138.1 


166.8 


174.0 


141.4 


225.0 


267.0 


287.6 


66 


104.5 


124.2 


148.6 


162.5 


181.0 


199.2 


234.4 


268.0 


300.0 


68 


?08.4 


128.9 


149.0 


168.8 


188.1 


207.0 


243.8 


278.9 


812.6 


60 


112.3 


138.6 


154.6 


176.0 


195.1 


214.9 


253.2 


289.8 


826.0 


62 


116.2 


138.3 


160.0 


181.3 


202.1 


222.7 


262.6 


800.8 


887.6 


64 


120.1 


143.0 


165.4 


187.6 


209.2 


230.5 


271.9 


811.7 


360.0 


66 


124.0 


147.7 


170.9 


193.8 


216.2 


238.3 


281.8 


822.7 


362.5 


68 


127.9 


152.3 


176.4 


200.0 


223.2 


246.1 


290.6 


836.6 


876.0 


70 


131.8 


157.0 


181.8 


206:3 


230.3 


253.9 


300.0 


844.6 


887.6 


72 


135.7 


161.7 


187.7 


212.6 


237.8 


261.7 


309.4 


366.6 


400.0 


74 


139.5 


166,4 


192.8 


218.8 


244.8 


269.6 


818.8 


866.4 


412.6 


76 


143.5 


171.1 


198.3 


226.0 


261.8 


277.3 


828.1, 


877.8 
^888.8 


426.0 


78 


147.4 


175.8 


203.7 


231.3 


258.4 


286.2 


837.6 


487.6 




.80 J 


151.3 


180.5 


209.2 


287.6 


265.4 


293.0 


840.9 


899.2 


460.0 





CUBIC MEASURE. 


( 


Inches. 

1. 

1728. 

4^656. 


Foet Yard. 
=t 0005788 = .000002144 = 
1. .03704 
27, 1- 


Cubir Metreii 

.000016386 

.028315 

764513 



A CUBIC FOOT IS EQUAL TO 



1728 cubic inche.<? 
.037037 cubic yard 
803564 U 8 struck bushel 
of 2150 42 cub. in 
3 21426 U S pecks 
7.48052 U. S liquid gallons 

of 231 cub in. 
a.4285l U. S dry gallons of 
268 8025 cub in 



29 92208 U. S. liquid quarts. 
25.71405 U S dry quarts 
59 84416 U S liquid pints 
51.42809 U S, dry pints. 
239.37662 U.S. gills 

.26667 flour barrel of 3 

struck bushels 
.23748 U S. liquid barrel 
of 31 >^ gallons 



A cubic inch of water ai 62^ Fahr weighs 252.458 grains. 
A cubic foot of water ai 62 Fahr weighs 1002.7 ounces. 
A cubic yard of water at 62'' Fahr. weighs 1692 pounds 



FRENCH CUBIC OR SOLID MEASURE. 



Centilitre . 
Decilitre 
Litre j 

Decalitre ] 

Hectolitre ^ ] 

Kilolitre ot \ 
Cubic Metre / 

MyrioHtre •! 



Dry .. 
Liquid 
Dry . . 
Liquid 
Dry .. 
Liquid 
Dry 



Liquid 21 13 
Dry 

Liquid 211 3 
Dry 
Liquid 
Dry . 

Liquid 



Pint Quart. 



.0181 
.0211 
.1816 
.2113 
1,816 
2.113 



0908 
1056 

.908 
1.056 

9 08 
10 56 
90.8 
105 6 

1056 5 

10565. 



Bush. 



2887 



2.837 

28.37 
283.7 



Cubic Inch. 



I 61016 
I 6.1016 
61.016 
610.16 
6101 6 
61016. 



Cu Ft 



.0363 
.3531 
3.53J 
35.31 
353.1 



35^) 



AVOIRDUPOIS WEIGHT. 

The standard avoirdupois pound is the weight of 27.7015 
cubic inches of distilled water, weighed in the air, at 39.83 
degrees Fahr. , barometer at thirty inches. 



Ounces. 


Pounds. 


Quarters, 


Cwt.8. 


Ton. 


1. 


= .0635 


= .00223 = 


= .000558 


=: .000028 


t6. 


1. 


.0357 


.00893 


.000447 


44t8. 


28. 


1. 


.25 


.0125 


1792. 


112. 


4. 


1. 


.05 


35840, 


2240. 


80. 


20. 


1. 



7000 grains 
5760 grains 



A drachm = 27.343 grainsi 

A stone = 14 pomids; 

A quintal = 100 kilogrammes^ 

= 1 avoir, pound — 1.21528 troy 
= 1 troy pound — .82285 avoir. 



Kilos p. sq. centim. 
Pounds p. sq. inch 



pounds; 
pound. 

14.22 = Pounds p. sq. inch. 
.0703 := Kilos p. sq. centim. 



FRENCH WEIGHTS. 

EQUIVALENT^TO AVOIRDUPOIS. 



Milligramme 

Centigramme 

Decigramme . , _ . _ . 

Gramme 

Decagramme .. 

Hectogramme 

Kilogramme ..-, _. 

Myriogramme 

Quintal 

Millier or Tonae. . 



.015433 
.154331 
1.54331 
15.4331 
154.331 
1543.31 
15433.1 



Ounces. 


f»J0352 


.003527 


.035275 


352758 


3.52758 


35.2758 


352.758 


3527 58 


85275.8 



Pounds, 



.000022) 
.000220) 
.002204 
.022047 
.220473 
2.20473 
22.0473 
220.473 
2204.73 



357 



SQUARE MEASURE. 



1 

144. 

1296. 

39204. 

6272640. 



Inches Feet. Yard I'erche.s. Acre. 

C00772 - .0000255 - .000000159 
111 .00367 .000023 

.0331 .0002066 

1. .00625 

160 1 

= 1 square. 

- I acre. 
= 8 acres per mile. 

- 2.471143 acres. 
= 27,878.400 square feet. 
= 3,097.600 square yards. 

( - 640 acres. 

Acres x 0015625 — square milei 

Square yard x 000000323=: square miles 
Acres x 4840= square yards 

Square yards X 0002066 nacres. 
A section of land is 1 mile square, and contains 640 acres, 
A square acre is 208 71 ft at each side; or, ; 20 k 198 ft. 
A .square ^ acre is 147 58 ft at each side, or, 110 x 198 ft. 
A square i acre is 104.855 ft. at each side. or. 55 x 198 ft. 
A circular acre is 235 504 ft in diameter. 
A circular ^ acre is 166 527 ft, in diameter. 
A circular i- acre is 117.752 ft m diameter 



Feet. 

.00694 

1. 

9. 1. 

2721. 30i 

43560. 4840. 

100 square feet 

10 square chains 

1 chain wide 

1 hectare 

1 square mile 



FRENCH SQUARE MEASURE. 



Square 


Square locliea 


Square Feet 


Square Vftrds 


Millimetre. 


00154 


0000107 


000001 


Centimetre 


15498 


.0010763 


.000119 


Decimetre 


15 498 


107630O 


011958 


Met cr Ccn 


1549 8 


10 76305 


1 19589 


Decametre 


154988 


1076 305 


119.589 


Hectare 




107630 53 
10763058 


1195S 9:. 


Kilometre . 


'.38607 amis 


1195895. 


Myriamei. . 


38.607 





. . . ^ 



358 



SURVEYING MEASURE. 



Inches, 

1. 

12. 



792. 



Feet. 



1. 
3. 

66. 

5280. 



(LINEAL.) 



Yards. 



Chains. Mile. 

= .0278 = .00126 = .0000153 

.333 .01515 .000189 

1. .04545 .000568 

22. 1. . .0125 

1760.> 80. , 1. 

.07 feet = 1855.11 



One knot or geographical mile = 
metres = 1.1526 statute mile. 

One admiralty knot = 1.1515 statute miles 



6080 feet. 



LONG MEASURE. 



Inches. 

1. 

12. 

36. 

198. 
7920. 



Feet. 



Yards. 



Poles. 



Furl. 



= .083 = .02778 
1. .333 

3. 1. 

16i. 5i. 
660. 220. 



: .005 = .000126 

.0606 .00151 

.182 .00454 

1. .025 



63360. 5280. 1 



40. 
320. 



Mlie. 

.0000158 

.0001894 

.000568 

.003125 

.125 



1- 



A palm = 3 inches. A hand = 4 inches. 

A span = 9 inches. A cable's length = 120 fathoms.^ 



FRENCH LONG MEASURE. 





Inches. 


Feet. 


Yards. 


Mflos. 


Milliinclre 


.03937 
.39368 
3.9368 
39.368 
393.68 


.0083 
.0828 
.3280 
3.2807 
32.807 
328 07 
3280.7 
328C7. 






Centimetre 






Decimetre 

Metre 

Decametre 

Hectometre 


.10936 
1 09357 
10.9357 
109 357 
1093 h'-f 
10935.7 


" 062134 


Kilometre 




621346 


Mvr'M metre 




6 2l3'tt)6 



359 
STRENGTH OF MATERIALS. 

ULTIMATE RESISTANCE TO TENSlOS 
IN LBS. PER SQUARE INCH. 

METALS. 

ATer&gt. 

Brass, cast, • - 18000 

" wire. . - 49000 

Bronze or jnn metal, - . ^ - . . 36000 

Copper, cast. - - 19000 

sheet, - 30000 

bolts, - *- 36000 

wire, . * . . . . 60000 

Iron. cast. 13400 to 29000, - . - - - . 16500 

** wrought, round or square bars of 1 to 2 inch 

diameter, double refined, - 60000 to 54000 

•• wrought, specimens yi >nch square, cut from large 

bars of double rehned iron, - 50000 to 63000 
•• wrought, double refined, m large bars of abouf 

7 square inches section, - - 46000 to 47000 

wrought, plates, angles and other shapes. 48000 to 61000 

plates over 36" wide. - 46000 to 60000 

Wrought iron, suitable Inr the tension members of bridges, 
should be double refined, -ind show a permanent elongation of 
20 per ct-nr in fi", when broken m small specimens, and a re- 
duction of area of 25 per cent at point of fracture 

The modulus of elasticity of Union Iron Mills' double refined 
bar ,ron <s 25000000 to ^16000000. from tests made on firushed 
eyebars 

Iron. wire. 70000 to 100000 

wire-ropes, . • . - - 90000 

Lead, sheet. 3300 

Steel, - 65000 to 120000 

Tin, cast, 4000 

Zinc, 7000 to 8000 



360 

STRENGTH OF MATERIALS. 

(continued.) 



TIMBER, SEASONED, and OTHER ORGANIC FIBER. 

Average 
Ash, Englisb, ^ - -« - - - - 17000 

« American, - - ^ * - 11000 to 14000 
Beech, " ^ * *► - - 15000 to 18000 

Box, ----»-.*--- 20000 
Cedar of Lebanon, - - ^ ^ - - - 11400 
** American, red, - - * - - / - 10300 

Fir or Spruce, _ - ^ - - 10000 to 13600 

Hempen Ropes, - - * ^ - 12000 10 16000 

Hickory, American, - - - - 12800 to 18000 

Mahogany, 8000 to 21800 

Oak, American, white,^ - - - - »- - 18000 

" European, - -. - - - 10000 to 19800 
Tine, American, white, red and pitch, Memel, Riga, - 10000 
long leaf yellow, - 12600 to 19200 

Poplar, - - . ^ - - . - - - . 7000 
Silk fiber, - . - - - - ' 62000 

Walnut, black, - ^ _• i . - 16000 

STONE, NATURAL AND ARTIFICIAL. 

Brick and Cement, - ^ - - - - 280 to 300 

Glass, - - ' -/ -,...-•- 9400 

Slate, -...-.-- 9600 to 12800 
Mortar, ordinary, _•«-**- 50 

ULTIMATE RESISTANCE TO COMPRESSION. 

METALS. 

Brass, cast, « . - - ^ r - - 1030O 

Iron, '* - - i , 3 . 82000 to 145000 
" wrought, ^ * - - - 36000 to 40000 



361 
STRENGTH OF MATERIALS. 

(CONTINUED.) 

TIMBER, SEASONED, COMPRESSED IN TH^ 
DIRECTION OF THE GRAIN 

Average. 



Ash, American, 
Beech, _ - - - 

Box, - - - - . 

Cedar of I^ebanon, 

" American, red, 
Deal, red, - - 
Fir or Spruce, 
Oak, American, white, 

" British, 

*' Dantzig, - - - 

Pine, American, white, 

" " long leaf, yellow 

Spruce or Fir, 
Walnut, black, - - 



4400 to 5800 

5800 to 6900 

10300 

5900 

COOO 

6500 

5100 to 6800 

7200 to 9100 

10000 

7700 

5000 to 5600 

8000 

5800 to 6900 

7500 



STONE, NATURAIv OR ARTIFICIAL. 



Brick, weak, - - - 

*' strong, _ . - 

•♦ fire. 

Brickwork, ordinary, in cement, 
" best. 

Chalk, 

Granite, _ . - 

Limestone, _ - . 

Sandstone, ordinary, 



550 to 800 

1100 

1700 

300 to 450 

1000 

330 

5500 to 11000 

4000 to 11000 

4000 



ULTIMATE RESISTANCE TO SHEARING 



METALS. 

Iron, cast, - - - - - - 27700 

" wrought, along the fiber, - - 45000 

TIMBER, ALONG THE GRAIN. 

White Pine, Spruce, Hemlock, - - 500 to 800 

bellow Fine, long leaf, - - - - 630 to 960 

Oak, European, _ _ _ . - 2300 

^.sli, American, ----- - - 2000 



3^2 

/able of Safety Load of Cast Iron Columns— Factor of Safety 10. 

This factor of safety of lo has been adopted to allow for Imper- 
fections in casting; such as air-holes, unequal thickness of metal, 
etc., devietion of pressure from axis of columns, and the effect of 
latenal forces accidentally applied. Where these risks do not 
occur, a factor of 6 may be taken for safe load. Ends of columns 
should always be turned true. 



^ ■ . 

'q48u8i JO 5003 
■j8d euujr.ioo 

JO -em ujiqSia^ 


— 05 CO! CJiOCsCt^ ©C:oS3Sp. 84f»«30r>ei »» 

r^'w sj— ceoceooieo oicsaioc^ ei-aDissisi ©c» 

— (N (N» ej©S"*'<»««5 W«»«»CO» »0»«t>iX» «« 


•saqooi 


OS® [>.« VD.S6,.99 ©lec-*^* X3srie^*i *05 
•*«c CO «>oo©i>(N «at>.xxp. ©»o5»95ie» ^^w 

ift r." fJ © X 04 «^ tC t»' (m' •«•* « X t> 3S — *" X X WW 
— ,-.^^« ^^.^MlM «> .« (M (£4 (M 9* f-ffi 






S 
^ 






i 








, 






^1 


QD 














• 


©X 








: • • • : ; 












i 


2t 






1 


: • • : : : 




,© — (NW •*/©.x©(yi^ ©ec 


5 


©1 


(» 


' : : : : 




••^M"**-®: '©C3 — ©S.Ot", ©J© 
;,ii,Mi-M »--n©l(N(M©J (MOl 


© 




©X r^ ©J 

aa©i ^lO «3>© — ©» — M«er^Ci ©'si^^eosw ■*©. 

^^rm ^^..p.,* •-• (M (M 9) (M CO (MOI 


QC 


J 


©ie« iO» i>.'»-(Nec^ «;cx©ei5 (N»i5X»-^t>. osm 

— — — — F-^»-(M(M We«<NCC*5CO «Je9 


OK 

Z 


Tons. 


WW »Ol> XM'* 


c 

c 


X ©35 — •*!>. ififfiM©©** *SX 
p. — — (N©1©I (NCJWWSC* WW 


•♦ 


CO 

c 


«>(X r-. .0 


(N ©»3»ftC5lM OS^XOliftX C^W 
ei — (N(J»©J©S dStM**"* «•» 




Z 

u 


ti 


06 

1 






1-4 . 


1 


«x* ©.» lij-Nifflxej «P-Ltr:««. asift-to — » ot© 




QC 


CD 

c 


«. M,M P-Oi©9C0^ eO M •>r -9 i.'i V.2«i2©r-r- »fl© 




«£ 


1 


OJ op 

^xii *^ COWixMf* ©(MX-*© —©©»«© ©« 
,i^^ m04 ©IMCO'*"'*' CO^-Tfi-'J© iCus;sr-roX ©© 


JO SSSTTHOim 




191803 


aqoai 




■^ kS i£ 




r» 




CO 






0> 



2P6 



TABLE OF SAFETY LOAD OF CAST IRON 
COLUMNS. 



(continued.) 



4ad 8uran[oo 


© 0? -<*'«--© t^ © 

CO©^*^©^- ^ 

e^OD©© — — (M 


CO CO r- SO iO © «N 
eaiNaD'M©! os«« 

OO OO r^ r^ «s •^ -«* 

«^ OD OS O — i^J -f 


CO OS «D CO OD or •* 

© CO ■» r- so so -.«< 

OD OD ©' OS OS OO © 
OS © — ©1 CO »ffl r- 


.-OS — 

c-'cs — 

o — OO 


•eoqoai 
U] V9IV [vnonoQs 


« 00 20 ^ •>* i-C © 

- « 'W. 3S OS © QO 


CSOOr^r-©©© 

©■^*«w«lOM 


©J © OS oc t>. so irv 

*ti OS CJ O t^ 00 .© 


SOTOI 

'(■OO — 


•a r- © «» »e t» OS 

(N w 99 »9 e« so e© 


.e OD — •* t>. © ■© 

-N -M CO CO « ">»"* 


-< ■* OC — •Wi © so 
CO CO CO 'T -^ »0 liO 


^X©1 

ooeo-ff 


' 


© 

00 


i 


t- © in ee © © *i 

M «« (M »1 S4 <»! m 


-•♦©CO — -*© 
"tl iM -M -M -0 CC •#• 


© ©1 .© X CO © lO 
CO SO CO CO ^ ■» •© 


©00 so 




04 


00 


© (N »/? t- iSIO -O 
(M •»» *1 -N ©;• M tc 


^ r- S « -^ OS .O 
•w; I CO CO ^5 5C ^ 


•r r^ — ^ GC so ■»♦• 

CO CO •»■ T -»• •© so 




Ul 


s 


OD 

1 


ecicoc— ^r-© 

e* <M <M so eo sc f 


r- © -!»< 30 — ■>* © 

. ©1 eo ©5 CO -* ■w -o 


OD ©1 ©©•*©« © 

SO -»■ -* .© .© JO • - 


XOr 3D 


Ik 


94 


1 


«©©HiSC3C— •»• 
»J ©» CO » CO •«»• «• 


© t* af5 (N « OS « 
OS 50 CO -r •*■*«? 


00 cr ©1 © — — — 
-»• •»• .© .C so r- 30 


OCX ■* 
.©lO© 


z 


a 


OS »J i« © ^ -c x< 


•* -r^ ©1 r- — ^ o 
CO CO -^ -* .= .^ -J 


X CO X ©» X o: O -'jc CO Z) 

-f .© .© so s: •- OS .0-cr- 


or 


s 

1 


w©os w;c =: — 


«- rtr- — .-; r: i« 

CO •*• ■» .o .<c .c » 


©« CD 00 X -r ■£ r> 
•o.csosoi---/: 35 


©1 OS so 

«SOl- 






«>. — .C JD s^ o o 
CO •«• •'^ •^ »o .o o 


©J I-- ^1 r^ ©1 r-. .>. 

-r -r .io .-5 CO so t^ 


OD -r © so CI -»• ti 
•CSOt- I', x-o: 2 


OSX 1- 
©c-X 


ta. 

oS 


to 


m 
a 


(Mo. —»OOSSOC>. 


r^ CO OD ■*»• OS .© .O 

-w lO lO sc so 1- 00 


f — X>©©lsO© 
set- «>-X O: S ©1 


so -» w 


•w 


i 


•*.OiOO©t-«- 


CO © © lo OS »e r- 
lO so » t^ t^ go OS 


^ c: i^ -r ©1 ac «*• 

l-l* X o: C: — CO 


C0©1 — 

ano-. o 


O 

z 

bJ 


CJ 


1 


.0!Mi»'SJacT© 
lO » © r» « . or OS 


O r« >»■ ©1 CC I/O OS 

<© SC l> 00 OC OS © 


OS X r^ .© CO © t>. 
.-■x ©©-©*•»• 

r- ;0 so »©<*©• © 
OO©© — ©I-*© 


©J©IC1 

c c — 


© 


P 


eo OS -.c 'M 3D -^ © 
so ;0 1^ 00 ao OS © 


r- .© CO — OO © ©1 
so 1^ OC OS OS © ©1 


«2 X o: 




ao 


66 

1 


«^ o. OD OS © © — 


CO CO ©1 — OS r- CO 

•^ 00 © © O — CO 


.(0 .© so © y; © © 

OS© — ©ICO .©1- 


© —CO 


1 


'* 


C 


ao r- .rt (N © TC SO 
r- OO © © — — 'M 


© © © © © X' © 
00 © © — -^ ©1 •'J" 


©1 -f I© .© so -.0 © 
O — ©icC-;0 /•- 


— ©1 •^ 


i<> 


ssau>i 


IM 


^^i^^^S 


:i^Nr^^^':'.-^ 


-f^ 


•saqoin i 


j| 


© 


o 


- 


©1 



;oiaiUTJ!(jap!S'ino 



3H 



TABLE OF 



SAFETY LOAD OF CAST IRON 
COLUMNS. 

(continued.) 

Oi — lOr- lO^QCOOQCiC or:'^?000— e-i-.-*r,|>.^ 
.-■"^^ ^ — ^^^^^1 ^^^^^-Mri ..- — — — ^OJl, 

OC;«»-* t^ r* — S5 «o ©a cs t>.— « O 

CXJeOC-Jr- «c; — — — _QtO OlkO — ifflODMCO 0«-©3io;5> 

•^-r>eo ec-^'TiO'OOO -*"*»ffl»o»oor>. ■» ■«!»■ >c «e » r» 

o 

r- 

oc 

o 

Oi 

1 

*' 

o 

©' 

<Ml 

COi 

9C< 

Oi 

•■ 1 
©9 " ^ »0 



■ .lad suiunioo 
JO -sqi ut 5qST5;V\ 



•saqoni 

iUI TBOJ-V, [BUOt:i00g 





o 


1 


C CC O t^ 

Iff, o o » 


O Ol GC -f C OD r- 

•*»• lO »<r CO i> c^ OD 


©©JGf3-*©^©5 

.© ;» CO r- 00 © © 


»© ©1 © r- <* €>• 

Oi>.r-ac ©© 




00 




" eoooco 


I— GO ■»?« © r- r- CD 
U2 »0 CC f ^ o. QO Ci 


♦1 CO ^ »- r» © )-< 
©©i^aoac©^ 


— oO'*cc©i«o 






CO 

C 




CO CO © CC »-C iC US 
»o CC 1^ !>. OC O © 


© CO © r>. "* r>. © 

©r-OCOOO©©* 


O i© CO ©1 © • 
1- 00 © © ^ ©1 






en 

a 


or- COO 


^ C5 t^ -!>"5^ ■<»« « 

e <© r- GC Si © »-i 


©J © X lO ce 00 ©1 
c»aoac©©T-o3 


CO OS ©I •-©r- 
oc©©P-©ios 


z 

ii 


©J 


00 

o 




r'. ./2 -<(■ CO I-"* © 
CO I- GC Oi © ^ (M 


oo r* .o ■«»• ©1 ac CO 
c>.aD©©^©ii!f 


©©©©©GD 
©©—©!«(■»♦< 






©laesr. 


V ) 

r-GC©©^(NCO 


lO ■*••»■ ec OJ © tv--' t- cc ©© ^ © • 


O S'. 


Of) 


c 

CD 

c 




»-< 1-1 l-« »-t 1— !>• (M 
OD Oi © T-i (M 99 iO 


©J CO eo M M ©1 « 
© © i-< ©1 CO 1© r- 


*©ao©*^»a 
© -« ©1 1»< Iffl l>- 


E 

OS 

X 


eo 




©.-KM ©I 09^00 

Oi © ^ (N w »o ce 


— ©1 CO -»> U2 © CS 
©F^©ISO-*©QO 


©lOOD'-OS© 
»-©IO?»©©© 




-i* 


a 


©35t-»0 


r- © »^ ©5 lO '(t- <N 

© © ©J ce •«*' © 00 


©1-ieoio©©.^ 

©©IOS'*>ffit»© 


©ccao»-»o©i 

©IOSi^©t»© 


O 

z 
llj 


o* 


00 

a 




© 1-1 OS •* »o t>» © 


t-©a«©oD©J© 
1-- as 1J- »o © © — 
^ « ^ ^ „ « (5, 


CC05r.©I©0l 
©1 •«*■ ifS t>- 00 1-1 


o 


OQ 

c 


(MCOiOr- 


-^©©-^QO©© 

i^ej-^usooo^ 

^ iM *« i>i< .M <-« «i 


.O © OS I- © © « 
O109^©CC©00 

;« fiN ^ t-« *« ©1 ©1 


©©lr.©lt5iO 

©SUOOODOSOI 
iM *i« *« w *M OI ■ 




00 


C 


■^iOr-© 


-^ce-*©*^©©! 
M^^^M©i©i 


^iC©-*©©01 


5C©iu3.Ml-.C0 

^»oc-©oco 




« 


a, 

C 


co»cc:m i'.(NaO'«»<©'#r>. 
•C«aC-- <M -^ iC r- Ci ^ «S 


CCWQOSaOD©-* 
e0»«©QDO>O»iO 

»-l — ^1^fM©l®l 


©t>.^^r..QD 

us©ao© — >* 


JO 






p^;^*;^ 


::?e:i?^:f?^ 




^S2^3S2 



•eaqooi ui | 



36s 

Crushing and Tensile Strength, in lbs., per square inch of Natum' 
and Artificial Stones- 



DBSCRTPTION. 



Aberdeen Blue Granite 

Qaincy Granite — 

Freestone, Belleville 

Freestone, Caen .. 

Freestone, Connecticut 

Sandstone, Acqula Creek, used for Capitol Wash 

Ington 

Limestone, Magneslan, Grafton. Ill 

Marble. Hastings, N. Y ... 

Marble, Italian 

Marble, Stockbrldge, City Hall, N. Y . . 

Marble, Statuary 

Marble, Veined 

Slate 



Brick, Red .• ^ 

Brick, Pale Red 

Brick, Common 

Brick, Machine Pressed 

Brick. Stock 

Brick-work, set In Cement, brlcka not very hard 

Brick, Masonry, Common 

Cement, Portland 

Cement, Portland, Cement 1, Sand 1 . 

Cement, Roman 

Mortar 

Crown GIa«8 



Portland Cement 

Portland Cement, with Sand 

Glass, Plate 

Mortar 

Plaster of Paris 

SlHie 



Weight 

per 

Cubicft 

in lbs 



164 
166 



165 



135.5 
130.3 



Crushing Force. 

Lbs, per Square 

inch. 



5.400 to 10,914 

15,300 

3,522 

1,088 

3,319 

5,340 
17,000 
18,941 
12,624 
10,382 
8,216 
9,681 
9,300 
808 ■ 
562 
800 to i,000 
5,222 to 14,^1* 
2,177 - 
521 
500 to 80O 
1,000 to S.SQO 
1,280 
S42 
120 to 240 

31,000 
TKN910N. 
427 to 711 
92 to 284 
9.420 
50 
72 
11,000 



Capacity of Cylindrical Cisterns.' 



FOB KACn FOOT OF DEPTH. 



Diameter 






Diameter 






In Feet. 


Gallons. 


Pounds. 


In feet. 


Gallons. 


Poundth 


2.0 


23.5 


196 


9.0 


475.9 


3^968 


2.5 


36.7 


806 


9.5 


580.2 


4,421 


8.0 


52.9 


441 


10.0 


587.5 


4,899 


3.5 


72.0 


600 


11.0 


710.9 


5,928 


4.0 


94.0 


784 


12.0 


846.0 


7,054 


4.5 


119.0 


992 


13.0 


992.9 


' 8,280 


5.0 


146.9 


1.225 


14.0 


1,151.5 


9,602 


5.5 


177.7 


1,482 


15.0 


. 1.821.9 


11.023 


«.o 


211.5 


1,764 


20.0 


2,350. 1 


19>596 


6.5 


248.2 


2 070 


25.0 


8,072.0 


80.620 


7.0 


287.9 


2,401 


30.0 


5,287.7 


44,098 


7.5 


330.5 


2.756 


35.0 


7,197.1 


60,016 


8.0 


376.0 


3,135 


40.0 


9.400.3 


78,f 38 


8.5 


424.5 


3,540 


.... 







PROPERTIES OF TIMBER. 



a^>l 


1 






1 


i. 


1 1 




11 


m 


2 


' ; i ; ; i 




i 




i 2 


1 


3 s 


1 






% 


1 


I § 




i 1 


if 


















2^23 


§ 






i 


s 


i 5 


12 


? ! 


S fi . 


t" 






o> 


^ 


■♦ 


00 


1^2 


3 






$ 





: 2 





2 ■; 


fi^ 


S 

'# 






i 


i 




i 


g 

CM ; 


£ s 


















go > 


















fii 


















g^ii 


2 


S CO £1 


2 S 





c- 


g 


g 


1 


^Is 




- «o — * 


c* « 


c» 


•- 






•-■ 





5 2 g 2 S B 


2 2 








2 i 


2 


! 


11^. 


i 


1 S " S £ 


S ^ 


i 


i 


s ■" 


^ 


s i 


33^ 












• 








e<9 


1 i i 11 






Si 




i 


i 


i:^ 


of 




» « 1 » -« 

S S ! fi s °. 


i 3 


§ 


3 


i 1 


OS 




i^ 

g 


* 


1 


11 i i i " 


tf. ^ 


00' 




«c c 


1 


f- 


■* 


n m* ' in « 


o» 


•* 


ifl 


10 


in 


n 
a ' 


1 


S, ; 5 


f 1 


; i 




: 1 


g 


§ § 
10 c 


^--• 


t^ 


* rf ' So 


00 r( 





s. 


• c 


oT 


C5> <£ 






— c 












-^5 





2 2 : ^ 3 § 


a f 


> 2 





\ "- 


o 


2 5 


Su5 


I 


00 : 2 * 


ei 5 ^' 


i 


c 


- 1 


g S 

c* 

2 o>' 


H 


'^ 




»» F 


r — 










^ a « 
















. 




•» 




1 ^- — 

: c^ ^ 


^ 






CO 


9 t* : 
















• 


"11 
















! 


^1. 


00 


T» 00 t- 






<n 






. 


in 


co «D ; «0 ! 

»ft , « I 






2 




s 


• 


-1 ^ J 
lie 





2 2 1 S? 2 j 


i 3 5 


2 

•1- 


' - ! 


• * 


^0 




-r « • eo • 






rt 




n 


' 


K 




! 1 ; ; : I 




; 








i i 


2 




i i I : i j 




• J 








' • 


K 








; J 








S ! 


S 




• '1*5' 




J 1 








; J 


D 




, 1 a S ^ , ! 




1 1 






! . 


■M 


8 


1 


i1l|IJl 

] n u u u X 




it 





i i 

a 


i 1 


'if 

1 s 



SQUARE CAST IRON COLUMNS. 

Safe Load in Pounds. Safety 6. 
Both Ends Turned. 



.a' 


Ontside^Size Columu, 8&8. 




Outside Size ColDmn, 10x10. 


*a 


54 in./ 


lin. 


l}^in. 


M in. 


lin. 


P/^in 


8- 


255,486 


328,902 


458,113 


10 


325,965 


422,874 


599,071 


^9 


247,656 


318,822 


444,073 


11 


318,015 


412,560 


684,460 


10 


239,457 


308,266 


429,370 


12 


309,751 


401,839 


669,272 


11 


231,786 


298,430 


416,670 


13 


301,232 


390,787 


553,615 


12 


222,400 


286,308 


898,787 


14 


292,640 


879,512 


537,662 


la 


213,752 


276,176 


388,280 


15 


283,752 


368.111 


621,790 


14 


204,896 


263,774 


267,399 


16 


274,925 


356,659 


605,267 


15 


196,642 


253,153 


252,606 


17 


266,109 


345,229 


489,075 


16 


188,268 


242,368 


337,584 


18 


257,362 


333.875 


472,989 


17 


180,126 


231,887 


322,986 


19 


248,709 


322,650 


45 7,087 


18 


172,220 


221,709 


808,810 


20 


240,204 


311.616 


441,456 


19 


164,589 


211,884 


295,125 


21 


231,873 


300,809 


426,146 


20 


157,242 


202,426 


281,950 


2^' 


223,720 


290,232 


4U,I62 


21 


150,225 


193,354 


269,314 


23 


215,881 


280,062 


396,754 


sa- 


148,462 


184,674 


25 7,224 


24 


208,083 


269,946 


382,428 


tis 


137,014 


176,376 


245,662 


25 


200,619 


260,263 


368,704 


SJ4 


130,881 


168,490 


234,682 


26 


193,398 


250,896 


355,434 


US 


126,349 


160,809 


223,985 


27 
21 


186,411 


241,830 


342,592 




Ontside S 


izeCalumn, 12x12. 


Ootside SizeColomn, 12x12. 




l.in. 


l>6in. 


2 in. 


lin. 


IJ^in. 


2 m. 4^ 


12 


616,846 


7 40,029 


989,720 


414,986 


594,184 


754,520 


18 


606,383 


7 25,048 


920,696 


22 


403,458 


57 7,678 


733,560 


14 


495,550 


709,537 


901,000 


23 


392,093 


561,406 


712,896 


15 


*484,418 


693,598 


880,765 


24 


380,864 


645,328 


692,480 


16 


473,057 


677,332 


860,104 


25 


369,829 


529,527 


672.416 


17 


461,579 


660,888 


839,160 


26 


359,005; 514.030 


652,736 


18 


449,913 


644,194 


818,024 


27 


348,401; 498.847 


633,456 


10 


438,253 


627,499 


796,824 


28 


337.731) 483.569 


614,050 


^5) 


426,593 


610,804 


775,624 


29 


329,941 469.552 


696.256 



COST OF LIVING IN CHINA. 
Land in China is divided into more holdings l!^n any 
other land in the world. It takes but a very small piece of 
land to support a Chinese family. The Chinese a*e the 
closest and most thorough cultivators in the world. Field 
hands in China are paid $I2 per annum. The food is 
cooked by the employer. With his food he is furnished 
straw, shoes and free shaving — the last a matter which a 
Chinaman never neglects for any great length of time where 
it is possible to secure the luxury. It costs about $4 a year 
to clothe a Chinaman. Much of the land in China is divided 
up into gardens of areas as small as one-sixth of an acre. 



368 
NOTES ON HOT WATER SYSTEMS. 

Let your " risers " not be less than i }^" , for smaller pipes 
soon become coated, if the water used contains lime or other 
matters in solution or suspension. 

Galvanized pipe is best; it does not become rusty and dis- 
color the water. 

In ordinary pipe be sure to get "galvanized steam," and 
0(Ot " galvanized gas. " 

Let your draw-off services be for bath i'\ to lavatories 
I", for hot water >^". Do not make the " draw- offs " too 
small, it takes too long to drain a pipe of cold water. 

The larger the pipes the freer the circulation, and, if you 
have hard water, they will remain in good order longer. 

Be sure that all joints are secure and free from leaks, and 
always look through a pipe before fitting it in place, to see 
that there is no dirt or impediment to the flow of the water 
through it. 

Avoid the use of elbows in circulating pipes, use only 
bends; if you cannot avoid using an elbow, see that it is a 
round one. 

TO SOLDER ALUMINUM. 

M. Bourbouze has formed an alloy of 45 parts of tin and 
55 parts of aluminum, which answers for soldering aluminum. 
This alloy possesses almost the same lightness as the pure 
aluminum, and can be easily soldered. M. Bourbouze has 
invented another containing only ten per cent, of tin. This 
second alloy, which can replace aluminum in all its applica- 
tions, can be soldered to tin, while it preserves all the prin- 
cipal qualities of the pure metal. 

A new and curious alloy is produced by placing in a clean 
crucible an ounce of copper and an ounce of antimony, and 
fusing them by a strong heat. The compound will be hard, 
and of a beautiful violet hue. This alloy has not yet been 
applied to any useful purpose, but its excellent qualities, 
independent of its color, entitle it to consideration. 

A CHEAP FILTER. 

A cheap filter which any tinner can make is 12x6 inches m 
size, and 8 inches high. The water flows in near the top, and 
on the top is a door through which to get into it to clean it. 
The outlet pipe at the bottom projects two inches up on the 
inside to hold the dirt back. A large sponge is placed inside, 
which forms the filtering medium, which, of course, can Dr 
cleaned as often as desired. 



3^9 

COMPOSITION OF BABBITT METAL. 

Genuine Babbitt metal, according to the formula of the 
inventor, is 9 of tin, i of copper. Antimony has been added 
since, so that the proportions by hundreds will stand So tin., 
5 copper, 15 antimony. For high speeds the metals should 
be cooler, giving a larger proportion of tin ; for weight the 
metal should be harder, giving a larger proportion of 
antimony. 

THE HEATING SURFACE OF A STEAM RADIA- 
TOR. 

For instance, the radiator contains 300 feet of one-inch 
pipe; what will be its heating surface in square feet? A. 
300. feet =3,600 inches. The outside circumference of one- 
inch piper=4 inches. And 3,600 X 4 = 14,400 square inches 
of heating surface. Lastly, 

14,400 

= 100 

144 
square feet of heatmg surface. The way you have calculated 
the heating surface is not correct, because you did not multi- 
ply the length of the pipe by the circumference. 

A CHIMNEY THAT WILL DRAW. 

To build a chimney that will draw forever, and not fill up 
with soot, you must build it large enough, sixteen inches 
square; use good brick, and clay instead of lime up to the 
comb; plaster it inside with clay mixed with salt; for chimney 
tops use the very best of brick, wet them and lay them in 
cement mortar. The chimney should not be built tight to 
beams and rafters; there is where the cracks in your chimney 
comes, and where most of the fires originate, as the chimney 
sometimes get red hot. A chimney built from the cellar up 
is better and less dangerous than one hung on the wall. 

ANCIENT USE OF LEAD. 

The ancients, like the moderns, used lead to fasten iron 
into stone, to give a glaze to pottery, and as a help to the 
manufacture of glass. Very singular were the " imprecation 
tablets, surrentitiously deposited in tombs, and sometimes 
even in the cotfin of the deceased, that a curse might follow 
him to the other world," which seem " to have been more 
frequently deposited by women than by men." VitruviuJ 
describes elaborately a vast aqueduct, the lead mi whicj 



370 

would cost to-day two millions. The leaden bullets of the 
ancient slingers often bore an inscription in relief such as 
« Appear," " Show yourself," "Desist," " Take this,"' " Strike 
Rome. " The Greeks were especially fond of bullets with 
Such mottoes, and they have been found upon Marathon and 
many other famous fields. 

A RUSSIAN WELDING PROCESS. 

The process of welding, invented by Mr. De Benardox, of 
Russia, is now applied industrially by the Society for the 
Electrical Working of Metals. The pieces to be welded are 
placed upon a cast-iron plate supported by an insulated table, 
and connected with the negative pole of a source of electricity. 
The positive pole communicates with an electric carbon in- 
serted in an insulating handle. On drawing the point of the 
carbon along the edges of the metal to be welded, the oper- 
ator closes the circuit. He has then merely to raise the point 
sligntly to produce a voltaic arc, whose high temperature 
melts the two pieces of metal and causes them to unite. The 
intensity of the current naturally varies with the work to be 
done. For regulating it, a battery of accumulators is used, 
and the number of the latter is increased or diminished as 
need be. This process of welding is largely employed in the 
manufacture of metallic tanks and reservoirs. 

COLD SOLDER. 

La Metallurgie gives the following receipt for cold solder: 
Precipitate copper in a state of fine division from a solution 
of sulphate of copper by the aid of metallic zinc. Twenty 
or thirty parts of the copper are mixed in a mortar with con- 
centrated sulphuric acid, to which is afterward added seventy 
parts of mercury, and the whole triturated with the pestle. 
The amalgam produced is copiously washed with water to re- 
move the sulphuric acid, and is then left for twelve hours. 
When it is required for soldering, it is warmed until it is 
about the consistency of wax, and in this state it is applied 
to the joint, to which it adheres on cooling. 

TO TIN MALLEABLE IRON. 

W. M. writes : I tin malleable iron, which comes from the 
bath nice and bright, but although I keep it covered, after 
few days it gets red, copper colored in spots, and this color 
gradually spreads all over the work. Can you tell n;c the 
cause ? A — The red color is probably derived from oxida^ 



37^ 

tioi? of the iron by the acid left in the pores of the iron. 
The acid rusts the iron and oozes out through the pores of 
:he tin by the pressure due to increase of bulk by the action 
?f the acid upon the iron ; possibly also moisture may be 
hsorbed by the acid through the tin, which is porous, 
Rinse the work immediately after tinning in boiling water, 
holding 2 oz. sal soda to the gallon in solution. 

OLD TINS NO LONGER USELESS 

A number of people recently gathered at the Colurrxbli 
"oiling mill, Fourteenth street and Jersey avenue, Jersey City, 
at the formal opening of the mill. The industry is a novel 
one, being the manufacture of taggers' iron from old tin cans, 
and other waste sheet metal. This iron has heretofore been 
manufactured almost exclusively in Europe, and the Columbia 
Rolling Mill Company is the only American company which 
turns out the product in large quantities. The process is 
simple. The tin cans are first heated in an oven raised to a 
temperature of about i,ooo^, which melts off the tin and lead. 
The sheet iron which remains is passed first under rubber- 
coated rollers, and then chilled iron rollers, which leaves the 
sheet smooth and flat. After annealing and trimming, they 
are ready for shipment. The tin and lead which is melted 
from the cans is run into bars, and is also placed upon the 
market. All the raw material used is waste, but the sheet 
iron turned out is said to be of good quality. It is used for 
buttons, tags, and objects of a like nature. The material used 
costing little, and the demand for taggers^ iron being consider- 
able, it is thought that this is a good opportunity to build up 
another American industry. 

LEAD ON ROOFS AND IN SINKS. 

Tenacity is very slight in some of the metals. An in- 
stance may be seen where roofs are covered with lead. The 
heat of the sun will expand them, and, of course, it is easier 
for the sheets to expand down-hill than up; then, when they 
get cold, their own weight will be too great for them, and 
they will sooner stretch than creep back up hill; so, in fact, 
unless properly laid, the lead roof will to some extent crawl 
off its frame-work. The same thing will be seen in kitchen 
sinks of lead, where very hot water is run into them. The 
lining gets wrinkled, because, after buckling by reasor '^f the 
expansion, it will sooner pull thinnei than come bach co the 
•^*dinary position and conditicn of surface. 



372 
THE USE OF THE STEEL SQUARE. 

The standard steel square has a blade 24 inches long and 2 inches 
v»ide, and a tongue from 14 to 18 inches long and \% inches wid<" 
The blade is exactly at right angles with the tongue, and the angx;; 
formed by them an exact right angle, or square corner. A proper 
square should have the ordinary divisions of inches, half inches, 
quarters and eighths, and often sixteer.ths and thirty-seconds. 
Another portion of the square is divided into twelfths of an inch; 
this portion is simply a scale of 12 feet to an inch, used for any pur- 
pose, as measuring scale drawings, etc. 'I'he diagonal scale on the 
tongue near the blade, often found on squares, is thus termed from 
its diagonal lines. However, the proper term is centesimal scale, 
for the reason that by it a unit may be divided into 100 equal parts, 
ond therefore any number to the looth part of a unit may he expressed. 
3ii this scale A B is one inch; then, if it be required to take off 73-100 
kiches, set one foot of the compasses in the third parallel under i at 
j&, extend the other foot to the seventh diagonal in that parallel at G, 
and the distance between E G is that required, for E F is one inch and 
F G 73 parts of an inch. 

Upon cne side of the blade of the square, running parallel with the 
length, will be found nine lines, divided at intervals of one inch into 
sections or spaces by cross lines. This in the plank, board and 
scantling measure. On each side of the cross lines referred to are 
figures, sometimes on one side of the cross line, and often spread 
over the line, thus, i ] 4 — 9 | — We will suppose we have a board 12 
feet long and 6 inches wide. Looking on the outer edge of the blade 
we find 12; between the fifth and sixth lines, under 12, will be found 12 
again; this is the length of the board. Now follow the space along 
toward the tongue till we come to the cross line under 6 (on the edge 
of the blade), this being the width of the board; in this space will be 
found the figure 6 again, which is the answer in board measu^-e, viz., 
six feet. ^ ^- . 

On some squares will be found on one side of the blade^g lines, 
and crossing these lines diagonally to the right are rows of figures, as 
seven is, seven 2s, seven 3s, etc. This is another style of board 
measure and gives the feet in a board according to its length and 
width. 

In the center of the tongue will generally be found two parallel 
Jines, half an inch apart, with figures between them; this is termed 
the Brace Rule. Near the extreme end of the tongue will be found 
24-24 and to the right of these 33-95- The 24-24 indicate the two 
sides of a right-angle-triangle, while the length of the brace is indi- 
cated by 33.95. This will explain the use of any of the figures in 
the brace rule. On the opposite side of the tongue from the brace 
rule will generally be found the octagon scale, situated between 
two central parallel lines. This space is divided into intervals and 
numbered thus : 10, 20, 30, 40, 50, 60. Suppose it becomes neces- 
sary to describe an octagon ten inches square; draw a square ten 
inches each way and bisect the square with a horizontal and per- 
pendicular center line. To find the length of the octagon line, 
place one point of the compasses on any of the main divisions of the 
scale and the other leg or point on the tenth subdivision. 



3/3 

ENDLESS TIN PLATES. 

A patent has been recently granted for a novel process of 
manufacturing continuous tin plates. The plates are made 
of steel, and the process consists of producing a sheet of 
st>eel of any continuous length and of required width, by 
first rolling the metal hot and afterward rolling it cold, 
until a proper thickness and perfectly smooth surface is 
obtained. Next, the surface of the sheet is scoured, and 
then it is afterward passed through a bath of molten tin, 
thus receiving its coating. Finally the sheet is subjected to 
a rolling operation, under heavy pressure, between highly 
polished rolls, by which the tin and steel are condensed and 
consolidated together, and the surface hardened and pol- 
ished. The inventor states that, by this method, the tin 
will be found to be so hardened upon and incorporated with 
the steel, as to produce a tin plate which is superior, in most 
respects, to any tin plate, wherever produced. 

ORIGIN OF PORCELAIN. 

The Chinese, the pioneers in the art of porcelain manu- 
facture, began to make it nearly two centuries before the 
Christian era, and so careful were they to guard the secret 
of the art that nearly fifteen centuries lapsed before their 
neighbors, the Japanese, got any inkling of it. But once 
in their possession, the wily Japanese lost no time to profit 
by their knowledge. The few intrepid navigators of those 
days brought samples of both Chinese and Japanese ware 
to Europe, but not until early in the sixteenth century did a 
trade in it of any extent take place. Among the early im- 
porters were Portuguese traders, and to them, we owe the 
word porcelain, derived from the Portuguese porcellana, or 
sucking pig. When the Portuguese traders first saw pieces 
of Japanese ware they were struck w^ith its translucence, 
which somewhat resembled that of the cowry shell. The 
cowry shell resembled a small sucking pig, hence our 
"porcelain." 

CRYSTALLIZED TIN [PLATE. 

Crystallized tin plate has a variegated primrose appear- 
ance, produced upon the surface by applying to it, in a 
heated state, some dilute nitro-muriatic acid for a few sec 
ends, then washing it with water, drying, and coating it 
with lacquer. The figures are more or less diversified, ac. 
cording to the degree of heat and relative dilution of the 
acid. 1 Place the tin plate, slightly heated, over a tub of 



374 

water, and rub its surface with a sponge dipped in a liquid 
composed of four parts of aquafortis and two of distilled 
water, holding one common salt or sal-ammoniac in solution. 
When the crystalline spangles seem to be thoroughly brought 
out, the plate must be immersed in water, washed either with 
a feather or a little cotton, taking care not to rub off the 
film of tin thc^- forms the feathering, forthwith dried with a 
low heat, ana ccsted with a lacquer varnish, otherwise it loses 
its luster in the air. If the whole surface is not plunged at 
once in cold water, but is partially cooled by sprinklins water 
on it, the crystallization will be obtained by blowing cold air 
through a pipe on the tinned surface, while it is just passing 
from the fused to the solid state. 

USEFUL EECIPES. 

Tinning Acid for Zinc or Brass.— Zinc. 3 oz.; muriatic acid, 
1 pt. Dissolve, and add 1 pt. water and 1 oz. sal-ammoniac. 

To Solder Brass Easily.— Cut out a piece of tin foil the size 
of the surface to be soldered. Then apply to the surface 
a solution of sal-ammoniac for a flux. Place the tin foil 
between the pieces, and apply a hot soldering-iron until the 
tin foil is melted. 

To Solder Without Heat.—meel filings, 2 oz. ; brass filings, 
2oz.; fiuoric acid, Ij^ oz. Dissolve the filings in the acid, 
and apply to the parts to be soldered, having first thoroughly 
cleaned the parts to be connected. Keep the fluoric acid in 
earthen or lead vessels only. 

To Tin Brass and Copper.— Mafke a mixture of 3 lbs. cream 
of tartar, 4 lbs. tin shavings, and 2 gallons water, and boil. 
After the mixture has boiled sufficiently, put in the articles 
to be tinned, and continue the boiling. The tin will be pre- 
cipitated on the articles. 

TO POLISH NIOKEL-PLATE. 

To brighten and polish nickel-plating and prevent rust, 
apply rouge with a little fresh lard or lard oil on a wash- 
leather or piece of buckskin. Rub the bright parts, using 
as little of the rouge and oil as possible: wipe off with a 
clean rag slightly oiled. Repeat the wiping every day and 
the polishing as often as necessary. 



375 



PATTERN FGK FLARING OVAL ARTICLES. 

Of all the great, variety of patterns with which the tin man 
has to deal, there is probably none that seems more difficult 
and causes mere troub'e and perplexity to make thana flaring 
oval pan. By following the annexed diagrams and explana- 
tions, the deve-Opment of this pattern will be seen to be sim- 
ple, easy and quickly per- 
formtcl 

First, always describe the 
oval from two centers — thus 
making the bottom of the dish 
— parts of two diameters or 
circles. Separate the circles 
when they intersect each other, 
and proceed the same as in any 
round, flaring article. 

In Fig. I the compasses 
are set at a a, and the large circles described as A A B B, then 
set the compasses 'd.\. b b and describe the smaller circles, thus 
completing the oval or bottom of pan. 

To make the pattern for the body : In Fig. 2 mark A B 






tlie size of large diameter. Then draw the depth of vessel 
and flare desired, as A B C D. Extend the lines C A anc 



J 



z^b 



D B until they cross at £?, set the compasses at ^^ and describto 
the curved lines C D and A B, Make the length A F equal 
to A A in Fig. i. Add the locks r.s shown in dotted lines; 
this will be the ] attern for side of dish. 

In Fig. 3, make a a equal to the small diameter and pro- 
ceed the same as in Fig. 2, this will be the end pattern. It 
takes two pieces of the large pattern and two of the small to 




Fig 4. 

make the dish. Should it be found desirable to mcike the 
body of pan in only two pieces, then cut the smaller or end 
pattern in two and place it upon each side of the large pattern, 
as shown m Fig. 4. 

An oval can be made from three or more centers upon the 
same plan when desirea. 



FLARING ARTICLES WITH 



f 




A 




. 




V 




J 




\ 


A 


/ 






p 
\ 




X " ( 


/ 



me se£:ments of thecircles a b; 



ROUND CORNERS. 

First, to cut the pat- 
tern of an oblong "^ar. 
ing dish with square- 
cornered bottom and 
round cornered top, 
in two pieces, of which 
Fig. I IS the grouna 
plan, and Fig. 2 the 
side elevation. 

The height of side 
A, Fig. 2, is from a to 
by which is also the 
radius for the corners. 
First mark off the side 
A, Fig. 3 ; then strike 
this gives the comer. Then 



6n 

murk off £)ne-half of end on each side oi a h [c and </), whicll 



Fig. 4. 



completes the pattern for 
one-half the dish. 

Fig. 4. For piactice, 
we will now cut the pat- 
tern so the bottom, sides 
and corners will be in one 
piece. 

One end of the seam 
comes on the end piece, 
and on the other end in 
the center of the corner piece. 

Fig. 5, B, shows cone made by putting together the two 
daring sides shown in Fig. 2, A. aad C, the pattern required 
to construct said cone D is the ground plan of cone B 







? 


r 






n 




b 





divided into four parts. It will bfe noticed that the four cor- 
ners in Fig. i will make D, and that the pattern for the four 
corners {a d A, Fig. 3) are equal to C, Fig. 5. 

As eacn corner of Fig. 1 
is one-fourth of a cone, so 
the pattern of each corner. 
Fig. 4, IS one-fourth ot the 
pattern C, required to mak? 
the cone By Fig. 5 

We will now suppose A, 
Fig. 2, to be the side view 
of a triangular dish con- 
on the same princiciple as A Each of the 




Struct ed 



sides v/ill be the same siz*, aJv^*t)aived to make the squaredislv 

only the pattern C, Fig. 
5, will be required to be 
divided into three partg 
for each corner of the 
triangle. Fig. 6 is a 
ground plan of bottom 
of dish. We will cut this 
pattern in one piece by 
marking off one of the 
rides, and then transfer- 
ing one-third of pattern 
Fig. 8. 




A, Fig. 7, to eacft 
side, until we have 
used the three sidq 
and three cornel 
pieces. 

The next step will 
be tvj cut the pattern 
of a flaring oblong 
dish, top and bottom 
having round cor- 
ners, of which Fig. 2 
will be a side view 
and A, Fig. 8, the 
ground plan. 

If the side and end 
pieces in A, Fig. 8, 
were removed, B 
would be the result. 
C is a side view and 
pattern for B. Now, 
if we wish a pattern 
for the A, all that is 
required is to cut the pattern for the four corners (C) into four 




179 



pieces, and place the .s:de and end pieces between, or, if the 

Fig. 9. 






pattern is wanted in two pieces, 
take a side on which we place two 
corners and a half of an end 
against each corner, as follows; 

Or we can suppose Fig. 10, B, 
to be the side view of dish having 
half-round flaring ends, but ends 
of different diameters, as shown 
by Fig. 10, A. 

We will have the small end 
the same as in Fig. 8, so as to use 
the same pattern. 

B, Fig. 10, showing side view 
and radius of large and small \ .•' 

circle. 

Fig. 10, C, giving the pattern for one-half of A, Fig. lO. 

To have the drawings appear plain, locks were not 
added. 

MAKING EAVE TROUGH. 

The outside line on the larger of the two small diagrams 

represents a No. 9 

\ ^<^^^^^^^^>K. spring wire clamp, 

1^^ y/^^^^^ ^^^^x^ ^"^ ^^ ^^ used at 

VCT I /// \\ ^^^^ seam of the 

"J /// V\\- trough. The dark 

IJ III y^l line on outside of the 

'~ - il __ ^ i smaller diagram rep- 

resents a small clamp 
used to hold the head down at the ends of the loii. The 



3^o 

large diagram shows the log with tb^ trough clamped to it. 
It will be seen that a 3^-inch piece is secured to the flat side 
of the log, which piece projects 3^ o'^ an inch beyond one edge 



of the log. A rocker may also be placed under the log. 
The log IS secured to the bench by hooks or staples with a 
long shank fastened to the bench and hooking onto spikes 
driven into the eids of the log. 



TABLE OF HEIGHT OF ELBOW ANGLEo. 



The following table gives the height of pitch of miter 
lines for elbows from one inch to twenty-five inches in 

diameter. It will be 
found of great assist- 
ance in describing el- 
bow patterns quickly 
and accurately, by do- 
ing away with draw- 
ings and geometrical 
calculations, which 
would otherwise be 
necessary to get the 
correct pitch of elbows. 
The accompanying dia- 
gram indicates the po- 
sition of base and 
miter lines. The 
height of pitch, that 
is, the length from O 
to W, IS shown by the table for all elbows from one inch to 
twenty-five inches in diameter, and of from two to ten 
pieces. In two-piece elbows the height of pitch is the diam- 
eter of the elbow, and this column is added to make the 
table complete. No matter how large the sweep of an el- 
bow, the angle of pitch remains the same, and the only dif- 
ference to be made in cutting the pattern is to add space as 
desired, as indicated at X in the diagram. Locks and seams 
are to be addedo 





^x, 










\\ ' 






\ \ ; 






\U 


/ 


Mi^:-^''"'"'^ 


,^ 




/\^ 


^^^^jj^ 




' 


v-^y 






B»» hit. 




>• 



3»i 






7 
8 

9 
lo 
II 

12 

13 
14 
15 
i6 

17 
i8 

19 

20 
21 
22 

23 
24 

25 













NO. OF 


PIECES 


IN ELBOW. 




2 


3 


4 


5 


6 


7 


- 


8 
1-8 




I 




7-i6 




9-32 




7-32 




6-32 




5-32 




2 




27-32 




18-32 




13-32 




11-32 




9-32 




1-4 




3 


I 


1-4 




13-16 




5-8 




1-2 




7-16 




11-32 




4 


I 


21-32 


I 


1-16 




13-16 




21-32 




9-16 




15-32 




5 


2 


i-i6|i 


5-16 








13-16 




11-16 




9-16 




6 


2 


1-2 


I 


5-8 




3-16 




31-32 




13-16 




11-16 




7 


2 


29-32 


I 


7-8 




3-8 




1-8 




15-16 




13-16 




8 


3 


5-i6;2 


1-8 




9-16 




1-4 


I 


1-16 




29-32 




9 


3 


23-32 


2 


13-32 




13-16 




7-16 1 


3-16,1 






lO 


4 


1-8 


2 


11-16 2 






9-16 




5-16 I 


1-8 


I 


II 


4 


1-2 


2 


15-162 


3-16 




3-4 




7-16,1 


1-4 


1 


12 


4 


15-16 


3 


3-162 


3-S 




7-8 




9-16 1 


3-8 


I 


13 


5 


3-8 


3 


7-8 2 


9-16 


2 


1-16 




23-32 




15-32 


I 


14 


5 


3-4 


3 


23-322 


3-4 


2 


7-32 




7-8 




9-16 I 


15 


6 


5-32 


4 




2 


31-32 


2 


3-8 


2 






11-16 

13-16 




i6 


6 


19-32 


4 


1-4 


3 


5-322 


17-32 


2 


1-8 






I? 


7 




4 


7-32 


3 


6-16 


2 


11-16 


2 


1-4 




15-16 




i8 


7 


3-8 


4 


25-32 


3 


9-16 


2 


27-32 


2 


3-8 


2 


1-32 




19 


7 


13-16 


5 


1-16 


3 


3-4 


3 




2 


1-2 


2 


1-8 




20 


8 


1-4 


5 


5-16 


3 


31-32 


3 


3-16 


2 


21-32 2 


1-4 


2 


21 


8 


5-8 


5 


19-32 


4 


5-32 


3 


11-32 


2 


13-162 


3-8 


2 


22 


9 


'-'^J. 


27-32 


4 


3-8 


3 


1-2 


2 


15-162 


1-2 


2 


23 


9 


7-166 


3-32 


4 


9-163 


21-32 


3 


1-16 2 


19-32 


2 


24 


9 


7-8 \6 


3-8 


4 


3-4 I3 


13-16 


3 


3-162 


11-16 


2 


25 


lO 


9-32 


6 


5-8 


4 


15-16 


3 


15-16 


3 


5-.6 


2 


13-16 


2 



1-8 

7-32 

5-16 

13-32 

1-2 

5-8 

9-16 

13-16 

29-32 

3-32 

3-16 

5-16 

3-8 

1-2 

19-32 

11-16 

25-32 

7-8 



1-16 

3-16,1 

9-322 

3-8 |2 
7-162 



10 

3-32 

6-32 

9-32 

3-8 

7-16 

9-16 

5-8 

23-32 

13-16 

29-32 

1-16 

5-32 

1-4 

11-32 

7-16 

1-2 

19-32 

11-16 

25-32 

7-8 

15-16 

1-32 

1-8 

3-16 



The table is adapted to right-angled elbows only. The 
line of figures at the top of the table indicate the number of 
pieces of which elbows are to be made. All other figures are 
in inches, the first or left hand column being the diameter of 
elbows, the remaining column being the height of pitch 
required. 

ZINC AS A FIRE EXTINGUISHER. 

Zinc, placed upon the stove, in fire or in grate, is said to 
have proved itself an effective extinguisher of chimney fires. 
To a member of the Boston Fire Department is reported to 
be due the credit of successfully introducing this simple 
scheme. When afire starts inside a chimney, from whatever 
cause, a piece of tin sheet zinc, about four inches square, is 
merely put into the stove or grate connecting with the chim- 
ney. The zinc fuses and liberates acidulous fumes, which, 
passing up the flue, are said to almost instantly put out what- 
ever fire may be there. It certainly sounds simple enougli. ^ 



3^2 

HOME-MADE ASH SIFTER. 

An Iowa correspondent sent Good Housekeeping the fol- 
lowing diagram and description of a home-made ash-sifter, 
any tinner or other person may construct : " I got my idea of 

it from seeing sand sifted by 
throwing it on a sieve that 
stood slanting. The wire 
sieve (already wove) can 
be bought at a hard- 
ware store for twenty 
cents a running foot, and it 
is two or two and a half 
feet wide, and this can be 
tacked to a frame made to 
fit the sifter, one end just 
reaching over the box for 
coal, and the other end ex- 
tending nearly to the top 
of the sifter. There is no 
shaking, nor any dust. 
Ashes are emptied in the 
top of the sifter, the coal 
being carried over the sieve to the coal box, while the ashes go 
through into the ash box. The sieve should be two and a 
half feet long. Can use a sliding or swinging cover." 

TO DESCRIBE A MITER. 

As there seems to be some interest manifested in regard to 
tb3 miter question, and nothing definite as to the desired 
miter has been given, I wish to submit the following rule: 

Let a in diagram be the size of the article upon which the 
miter is to be cut ; strike a circle full size, or from edge to 
edge as shown at e and b of the diagram ; draw a line as 
shown by d^ from e to b^ which divides the circle equally. If 








s 


c t 










\ 


\^ 


^ 


\ 




a 




»4\ 


d. 


) 

, . ■ ■ . 



you wish a square miter set compass at e and obtain one- 
fourth of the circle as shown at figure 2, and draw line by 



intersecting the circle where the point of the compass shows 
one-fourtii of circle. Cuttmg this hne you have a square 
miter. Should you wish your work to form six squares, take 
the sixth of a circle as shown at figure i by line c h ; or, if 
eight squares, one-eighth ^ f circle, and intersect the circle at 
point designated by compass. 

A miter may be cut for any angle desired by the same 
rule ; divide the circle into the number of squares wanted, 
and proceed as shown above. This rule does not apply to 
forming a miter for gutters. 



TO DESCRIBE A PATTERN FOR A FOUR-PIECE 
ELBOW. 



Three and four piece elbows have very largely taken the 
plr?xe of the old right-angled elbow, on accounf of their bet- 

ter appearance, and also 
ft .r . , i" — ,.-- , ■' r ? becaase they lessen ob- 

struction to draft. The 
machine-made article is 
k pt in stock for all 
common sizes, but the 
'inner is liable to be 
called upon at any time 
to make such an elbow, 
on account of stock be- 
ing sold out or of un- 
usual size, or other 
cause. Herewith are 
given diagrams and ex- 
planations which will 
enable any tinner to 
construct a pattern for 
any desired size. 

Let ABE D,Fig. i, 
A98 7 6 » A aaia ^e the given elbow; 
draw the line F C ; make F M equal in length to one-half 
the diameter of the elbow, with F as a center; describe the 
arcKL; divide the arc K L into three equal parts; draw 
theknes F II and F I ; also the line I II ; divide the section 
H K into two equal pn rts, and draw the line F G ; draw the 
lin3 A B at right angles to B C ; describe the semi-circle 
A N B ; div^'-'^ *he semi-circle into any number of equal 
parts ; from me points draw lines parallel to B C^ as I, 2, 3, 
etr,. 




3H 

Set off the line A B C, Fig. 2, equal in length to the cir- 
cumference of elbow A B ; erect the lines A F, B D and 




1 2 3 4 5 6 T 



C E ; set off on each side of the line B D the same number 
of equal distances as in the semi-circle AN B ; from the 
points draw lines parallel to B D, as i, i, 2, 2, etc. ; make 
B D equal to B G ; make A F and C E equal to A J ; also 
each of the parallel lines, bearing the same number as 1,1, 
2, 2, 3, 3, etc. ; then a line traced through the points will 
form the first section ; make F G and E J equal to H I ; re- 
verse section No. i ; place E at G and F at J ; trace a line 
from G to J ; make G H and J I equal to P O, Fig. 6*]^ or 
to D K, Fig. 68; take Sec. No. i, place F at H and E at 
I, and trace a line from H to I ; this forms_Sec. No. 3 
and 4. 

Edges to be allowed. 



In the West Indies the work of coaling ships is performed 
by negresses. Like ants going to and fro, each of these 
women, with a load of coal weighing about forty pounds, 
carried in a ba^iket on top of the head, climbs the gang-plank, 
and the bunkers are filled in a wonderfully short time. For 
this arduous work, a cent a basket is the general price, but 
night work and emergencies double the rate. A penn)' is 
given to each woman as she fills her basket, and the number 
given out forms a check on the tally kept by the parties 
receiving the coal. The name of the firm owning the coal 
pile is stamped on the coins, which are current throughout the 
slands 



3»5 

A WIRE FLOWER STAND. 

Tinners are ingenious, and can generally make anything 
from sheet metal, wire, or other light material, which they 
take a fancy to try their hands at. Many have made orna- 
mental articles at odd 
moments with which to 
beautify their own home, 
or possibly that of some 
young lady. By their 
skill in this direction 
they are frequently able 
to make presents of arti- 
cles of their own make, 
which are not merely or- 
namental, but also usefuL 
This is commendable, 
and such skill and enter- 
prise is worthy of encour* 
agement. 

We here present an 
illustration of a new 
round flower-stand con- 
structed in three parts^ 
which can be taken asun- 
der so as to convert the 
stand at will into a rustic 
table. The cut is taken from the London Ironmonger^ 
which says that the originator of the flower-stand is doing 
well with it. 




TO STRIKE AN OVAL OF ANY LENGTH OR 

WIDTH 

In a recent number of the American Ar'isan, which I 
have mislaid, some one asks for a rule to strike an oval of 
any desired width and length. There are several different 
ways of striking an oval or ellipse, but I find the one I en- 
close you the most practical. 

Let A B and C D equal width and length. On the line 
CD lay off the width of oval as CC. Divide the distance 
from E to D into thr e equal parts, and lay off two of the 
parts thus formed on either side of the center F, as G and 
H. Span the dividers from H to G, and, with F as a center, 
check the line A B, as at M and K. Draw line intersecting 
the points H M G K, and, with the radius G D and K B 
strike the ends and sides of oval. 



32^0 

AN ORNAMENTAL PAPER HOLDER. 

Tinners with leisure who desire to use their handiwork in 
Sialsing something for Christmas, will be interested in the 



accompanying illustration which we reproduce from a 
European journal. It is intended for a holder for paper, 
magazines, or sheet music. 

HEATING AND VENTILATION. 

Much continues to be said and written about heating and 
ventilation, and some may consider it a worn-out subject ; but 
so long as millions of people continue to be poisoned by 
impure air, jagitation to secure reform cannot be overdone. 
It will do no harm, therefore, to again name some of the evi- 
dences and consequences of a lack of ventilation : Head- 
ache ; dull pressure on the lungs ; lungs become parched, pro- 
ducing irritation; dryness of the throat, producing sore 
throat ; a fevensh condition of the whole system; These are 
«ome of the immediate consequences, but by no means embraa 



:PT 



all the ultimate evil effects. It should be the duty of aB 
f:imacemen to call the attention of their patrons to these 

c c , 




matters. Furnaces are often blamed for the quality of air 
supplied, while the fault lies solely with the operators in not 
making provision for the supply of pure air to the furnace, 
and proper ventilation. 

This subject will not take care of itself We must first 
feel that fresh air is worth taking some trouble to obtain, and 
then we must study how to obtain it without the body's 
becoming either chilled or overheated in summer or winter, 
in the daytime or in the night. At night more care needs to 
be taken to secure ventilation, because there are no doors 
being opened ; no stirring about to promote circulation. 
Especially should pure air be supplied to the sick room, and 
the vitiated air removed. 

In summer we depend on the natural movement of the air 
for ventilation, windows and doors being open more or less. 
In winter, with the liouse closed up, it requires thought and 
effort to provide for a change of air in apartments. It must 
be remembered that, under natural conditions, air moves hor- 
izontally, according to the direction of the wind. Heat causes 
air to move in a perpendicular direction. In dry weather, 
heated air and smoke will rise until the same density of atmos- 
phere is reached, which soon results from loss of heat. When 
the atmos]:)here contains a great deal of moisture, smoke \vill 
descend, on account of quick condensation and loss of heat. 
This principle, understood by all must be kept in view in 
any plan for ventilation. Suppose we wish to ventilate a 
loom in the morning when the air outside has become a little 
warmer than the air inside. The upper part of a window 
being opened the warmer air outside would blow ncross the 
top of the room, leaving the air below undisturbed, Now, 
if we open the v/indow at the bottom we shall secure a cir- 
culation of air in the room. While the outside air is warmer 
we do^not notice the draft. Suppose we now go i.ito the 
kitchen, where the windows are only opened at the bottom 
and raised halfway up; we shall feel the lower part is cool. 



388 



while the air in the upper part is undisturbed. Now, if we 
open the top of the window and divide the difference so as to 
have the top and Dottom open, we shall have a circulation. 
Or if we open a door and hold a candle at the top and then 
at the bottom, we will see the same circulation illustrated by 
the cold air flowing in at the bottom and the hot air out at 
the top. These experiments furnish the natural laws which 
should govern ventilation. 

Carbonic acid gas from respiration and other exhalations 
of the body, as well as gases caused by decayed vegetation in 
cellars, or from garbage, sewer emanations or any kind of 



^1^ 



lU 



\ 




V. 



Fig. 2 



■filthy are all poisonous, and, being heavier than pure air, sink 
to the bottom of a room by gravitation. It is a gross error 
to suppose, as many do, that the foul air rises to the ceiling 
and remains there. The sickness and death of children, often 
attributed to other causes, arises from blood-poisoning from 
the foul air near the floor to which children are much more 
exposed than grown persons. 

The illustrations given herewith will show where 
the foul air is and how it is confined unless drawn 
off by some superior force. In Fig. i, A represents a 
cellar, DD the walls, CC the surface of the ground outside of 
the house. . Foul air seeks the lowest space by gravitation, 
therefore all below CC is foul air because there is no ventila- 
tion to draw it away. So long as it remains stagnant, pure 
air will not take the place of the foul. Now, if we place a 
furnace in the cellar, as shown in Fig. 2, and take the air 
from the same, it would amount to almost the same thing as 
living in the cellar, for you breathe the same air. Opening 
^e windows furnishes an outlet for the warm air and thus 
lools off the furnace; but the same foul air, dust and ashes 
are brought up from the furnace for inhalation. 

Again, if the rooms are closed, the air from the furnace 
will rise to the ceiling, then pass to the windows, where the 



3»9 

temperature will be reduced, and will then descend to the 
floor and down the sides of the hot-air flue to the furnace to 
be reheated and sent up again. This has been proven by ex- 
periment. The children will be the first to be aft'ected by 
this reheated foul air. 

How can we obtain pure air? By ventilation. How can 
ventilation be secured? In various ways. The principal 
method used is the ventilating shaft. One shaft is generally 
sufficient for one dwelling, and is usually in the form of a 
large chimney, as shown in Fig. 3. A is the chimney; B is 
a heavy sheet-iron pipe, with air space around the pipe for 
ventilation; 6" is an opening into tne pipe B for connection 
with the furnace; Z>is a place for cleaning out just below the 
furnace opening; these two openings should be in the cellar 
where the furnace is; C is the place for the kitchen stove, 
which will supply sufficient heat for ventilating the house dur- 
ing the summer season. Fig. 3. 

We will next consider how to supply the 
furnace with pure air. It should be taken 
from the side from which come the pre- 
vailing winds. Of course, care should be 
taken that it is not polluted by a sewage 
hopper, water closet or other source of con- 
taination. The opening into the air-duct 
should be two feet or more above the ground, 
and should be covered with fine wire gauze. 
The air-duct should be carried along the 
ceiling of the cellar until it reaches the fur- 
nace, as shown by dotted lines in Fig. 2, 
then drop down at the side of the furnace to 
the bottom. The space around the furnace 
should be made air-tight. Any foul air in 
the cellar will be drawn into the fire-box of 
the furnace to promote the combustion of 
the fuel. The area of the cold-air duct 
should, in no case, be less than half the area 
of the hot-air pipes. 

In setting a furnace, particular care 
snould be taken to see that the chimney has 
a good draught. There should be sufficient height betweer 
the top of the furnace and the ceiling of the cellar to permil 
a good rise for all the hot-air pipes from the furnace. 
If there is not' sufficient height in the collar to admit 
of this, the furnace should be set into ? pit dug out 
below the cellar floor and bricked up. Ample room 
should be allowed in front of the furnace for cleaning 




out ashes. All the pipes should be kept as close to the 
furnace as possible. If any hot-air pipe is extended more 
than fifteen feet from it, it should be encased witl] about 
half an inch space around, with both ends of casing entirely 
closed, to prevent the loss of heat. The location of the 
furnace should be so that the length of hot-air pipes shall be 
about equal. The smoke-pipe should be run directly to the 
chimney. Dampers should be placed in all the hot-air pipes 
close to the furnace, and, when the pipes are not in use, the 
dampers should be closed. The vapor-pan should be placed 
where the water will not boil. In some cases, if set on the 
top of the furnace, the water will boil over and crack the 
furnace. A proper place must be provided for it. In a brick- 
set furnace, the vapor-pan should be automatic in action, 
being connected with an outside pan with a ball and cock. 
Without this arrangement it is hard to keep up a regular 
supply of vapor, as this is a point generally neglected. 

In order to distribute the heat through the rooms, the 
ventilating registers must be located in the proper places. 
They should be placed in the floor near the windows or in the 
coldest part of each room, so as to draw the heat to that 
part. Never run a hot-air pipe up an outside wall if you 
wish success with your work. If ventilators are put iato a 
side wall, be sure that they extend down entirely to the floor, 
otherwise there will be a cold stratum of air next the floor, 
causing cold feet. A failure to do this, causes children to 
have cold feet at school. People frequently suffer in a simi- 
lar way at church. 

LIQUID AIR, THE COMING FORCE. 

Water freezes at 32*^ above zero. Mercury in a ther- 
mometer freezes solid at 40-42^ below zero. The alcohol 
in a spirit thermometer freezes at 200^ below. Air becomes 
liquid at 312^ below zero. 

Eight hundred cubic feet of free air are condensed into 
one cubic foot of liquid air. One pint weighs one pound, 
like water. 

By the aid of a 50-horse power steam air-pump, ordinary 
air is compressed until it becomes red hot. Then it is 
cooled in submerged pipes, and is further compressed until 
the pressure is registered at thousands of pounds to the 
square inch. More cooling is done, more pressure applied, 
until finally the air liquifies. It oozes through the steel of 



391 

the pipe in the shape of a milky white vapor and trickles 
down into the receptacle below. 

As there is a difference of 344^ between the tempera- 
tures of ice and liquid air, it will be understood why liquid 
air boils furiously even when placed on a block of ice. 

A hand thrust in this liquid, in appearance' like water, 
would be destroyed in 10 seconds, but if drawn out in- 
stantly, the moisture of the skin freezing to ice would be 
protection enough. The feeling at touching the liquid is 
like that of iron at white heat. 

Like quicksilver, liquid air does not adhere. If poured 
over silk, it will leave no stain. 

When boiling, the vapor of liquid air, being nothing 
but highly-compressed air, sinks to the ground. 

If water is poured into liquid air it turns to ice instantly, 
and of such a low temperature that it will not melt near a 
red-hot stove for a long time. 

A stick of arc light carbon, heated to 2,000 degrees 
above zero, thrust into liquid air, causes the oxygen in it to 
burn with a dazzling bright flame. 

A teaspoonful of liquid air in a close vessel, if lighted, 
explodes with tremendous force, jarring the ground like an 
earthquake. 

The expansive power of liquid air is about 20 times 
greater than that of steam. 

•iTen years ago it cost about $2,000 to produce a gallon 
of liquid air. To-day, so Prof. Chas. E. Tripler, of New 
York, states, it can be manufactured at a cost of 3 or 4 
cents per gallon, at the rate of 40 or 50 gallons a day* 

A steam engine horse-power is now figured at $36.00 a 
year expense; by the use of liquid air it should not be 
more than $7.00. 

A pocket flask full of liquid air will furnish free air for 
a submarine apparatus for hours. 

EXPLOSION OF A DOMESTIC HOT WATER 
BOILER. 

Explosions of domestic hot water boilers attachea to 
cooking ranges, water-backs in ranges, etc., through freezing 
up of the pipes in cold weather, are becoming so frequent 
that it may not be out of place to give an account of one ot* 
the most destructive ones that has occurred recently, and 
point out its cause. 

The boiler in question was used in an hotel in a large cit^ 



392 

in one of the Northwestern States, where the temperature is 
very low at times. It was connected to the kitchen range, 
the range was a very large one, and the heating surface was 
furnished by a coil of j j^ inch pipe, placed near the top, 
mstead of the cast-iron front or back, such as is commonly 
used in the smaller ranges in private dwellings. The con- 
nections to the boiler were made in the usual manner ; the 
accompanying cut shows its essential features. 

The operation of all boilers of this sort is as follows : 
The connections being made, as shown in cut, the water 
is turned on from thv: main supply, and the entire system is 




fil. 1 with water. When it is filled, and all outlets are 
clobjtl, it is evident that no more water can run in, although 
the l)oiler is in free connection with, and is subjected to, the 
full pressure of the source of supply. When a fire is started 
in the range, and the water in the circulating pipes, or 
water-back, is heated, the water expands, is consequently 
lighter, nnd flows out through the pipe into the boiler at A, 
ns tliis C()niiecti;)n is ]ilaced higher up than the one at B; 
iliis siarts the circulation, and the water, as it becomes 



:i93 

heated, constantly flows into the boiler at A, and rises to the 
upper part of the holler, while the cooler water at the bot- 
tom of the boiler flows out into the circulating pipes at B, 
and, if no water is drawn, a slow circulation goes on, as heat 
is radiated from the boiler, in the direction indicated by the 
arrows, the water at the top of the boiler always being much 
hotter than at the bottom. When the hot cock is opened, 
cold water instantly begins to flow into the boiler at D, by 
reason of the pressure on the city main, and forces hot water 
out of the boiler at C. Thus it will be seen that hot water 
cannot be drawn unless the cold water inlet is free, and it is 
equally evident that cold water cannot enter the boiler unless 
the hot water cock or some other outlet is open. 

The above points being understood, we are in a position 
to investigate the cause of the explosion referred to, which 
killed one person and badly injured twelve or thirteen others, 
besides badly damaging the building. 

':|On the morning of the explosion Are was started as usual 
in the range about four o'clock a. m- It was found, on try- 
ing to draw water, that none could be had from either cold 
or hot water pipes; it was rightly judged that the pipes were 
frozen. The fire was continued in the range, however, and 
the breakfast prepared as best it could be, and a plumber sent 
for to thaw out the pipes. He arrived on the premises about 
seven o'clock, as would naturally be the case. He opened 
both hot and cold water cocks, and, getting neither steam nor 
water, concluded there was no danger, and proceeded to 
thaw out some pipes in the laundry department first. About 
an hour afterward the explosion occurred. The lower head 
of the boiler let go, and the main portion of the boiler shot 
upward like a rocket through the four stories of the hotel 
and out through the roof. ^ 

J The coroner held an inquest on the remains of the person 
killed, and some of the testimony given, as reported in a 
local paper, would be amusing were it not for the tragic 
nature of the affair which called it out. The usual expert, 
with the usual vast and unlimited years of experience, was 
there, and swore positively to statements which a ten-year- 
old boy who had been a week in the business ought to be 
ashamed to make. He had examined the wreck with a view 
to solving the mystery (?) The matter was as much of a 
mystery now as oh the day of the explosion. His theories 
were exploded as fast as he presented them. The boiler must 
have been empty. If it had been full of water, it could not 
possibly have exploded, etc., etc. And then a lot more 
nonsense about the "peculiar" construction of the boiler 



394 

AS a matter of fact, there was 7.iothiiig peciiliar about tlie 
boiler or its connections. Everything was precisely like all 
boilers of its class, of which there are probably hundreds of 
thousands in daily operation throughout the country, and, 
moreover, they were all right. 

Now let us inquire what caused the explosion. Every- 
thing was all right at eight o'clock the previous evening, for 
water was drawn at that time. The fire was built in the 
range at four o'clock a. m. It is admitted that the cold 
water supply pipes were frozen, for no water could be had 
for kitchen use. It is also proved absolutely that the hot 
water supply was frozen or otherwise stopped up, by the fact 
that at seven o'clock the plumber who came to thaw out the 
pipes opened the hot water cock and got "neither water nor 
steam." Here was his opportunity to prevent any trouble, 
but he let it pass. Any one who understood his business 
would have known that there must have been a tremendous 
pressure in the -boiler at this time, as the range had been fired 
steadily for three hours; there were about eight square feet 
heating surface exposed to tne fire by the circulating pipe in 
the range, and there had been no outlet for the great pressure 
which must have been generated during this three hours 
tiring. The blow-off cock should have been tried at once; 
if this were clear, and th8 probability is, from its proximity 
"".o the range, that it was clear, the pressure could have been 
relieved, and disaster averted. If the blow-off proved to be 
stopped up, then the fire should have been at once taken out 
of the range. At the time the plumber opened the cocks 
connecting with the boiler, it probably was under a pressure 
of 400 or 500 pounds per square inch. An ordinary cast- 
iron waterback such as is used in small ranges in private 
houses would have exploded shortly after the fire was built, 
but it will be noticed that the heating surface in this case 
was furnished by a coil of 1^-inch pipe; this was very 
strong, and the boiler was the first thing to give way, simply 
because it was the weakest part of the system. 

Accidents of this sort can be easily avoided by exercising 
a little intelligence and care. The hot water cock should 
always be opened the first thing on entering the kitchen 
every morning. If the water flows freely, fire may then be 
started in the range without danger- If it does not flow 
freely, don't build a fire until it does. 

A Cement to Make Joints for Gra-Nite Monuments— 
Use clean sand, twenty parts; litharge, two parts; quicklime, 
one part, and linseed oil to form a thin paste. 



395 



USEFUL SHOP KINKS. 

Fig. 1. A rule for different angles, or rise of elevations 
for elbows: 

The usual rise given to 
furnace pipe elbows is 
one incli to the foot. A 
rule to obtain the desired 
result is as follows, and 
is almost identical with 
the one commonly used 
to get the height and 
pitch of miter line of 
right-angled elbows. It 
is applicable to any sized 
throat and any sized el- 
bow; also, to elbows 
with any number of 
pieces or sections. 

First draw lines a c 
and c 6, Fig. 1, at right 
angles to each other. 
From point c on line c b, 
measure off 1 foot, and 
perpendicular from the 
point thus obtained erect 
line d to r, which is the 
desired height you wish the elbow to rise, or angle from a 
true right-angled elbow, in this case one inch to the foot. 
From point c as center, draw the arc a to r. From point r 
draw the line r c for base line. This will give the correct 
elevation, as proof clearly shows by the dotted lines c to z 
and r to m; these show the continuation that the elbow leads 
to, namely, as in this instance, 1 inch to the foot, or 1 foot 
in 12 feet. The line c to ic is 1 foot, and from xx,o z, 1 inch. 
|Tf an elbow of four pieces is desired, divide the arc or 
curve rto a into six equal parts; if an elbow of three pieces 
or sections is wanted, divide same into four equal parts. 
From point c for a four-piece elbow, draw line c to s, and 
from point n, where inner curve of elbow intersects line c s, 
draw line n lo I parallel to line c i\ and same intersecting 
linersat^. This much gives the pitch and rise for miter 
line for a four-piece elbow of the desired elevation. 4. For a 
three-piece elbow the dotted lines from i)oint k on the inner 




396 



curve Lo points u and o on outer curve, give the miter de- 
sired. 

I have also shown a FiG. "X, 

smaller-sized elbow in 
the drawing to show how 
the rule works, and is 
applied on same. It is, 
of course, not necessary 
to give the same size of 
throat, as is given in the 
drawing, nor the same 
outside sweep. This rule 
will suit any case or sized 
elbow as may be desired, 
and as one becomes fa- 
miliar with the working 
of the rule, some of the 
other lines need not be 
drawn out, but are here 
given to make the draw- 
ing complete. 

The above is given to 
get the complete data for 
side elevation which are 
necessary to develop the / 

patterns for the different 

sections of an elbow. To develop the same I will give a 
quick snap rule, which comes so near right as to be prac- 
tically almost correct. I will, however, tirst give a good 
snap rule for angles. 

If Fig. 3 is examined, it shows the usual long and tedious 
geometrical method of obtaining miter lines for both a two- 
piece, and also a three-piece angle, both of the angles being 
of the same pitch. The solid lines are for a three-piece angle, 
and the dotted lines are for a two-piece angle. 
•^Now, to do away with all this drawing, and to get a quick 
and very nearly correct method to obtain the desired result, 
suppose an angle is wanted as is given by the lines a h and 
a to c. Fig. 3, the diameter to be as full drawing requires, 
proceed as follows: First measure off the distance which is 
the size of diameter wanted, from a lo h; do the same frbm 
a to c, and from points thus obtained, which are c and &, 
draw the line d from c to h. Then from either line, a c or 
line a 6, draw at right angles the line a to ic, as shown, the 
line a x intersecting line d at x. This mucn gives tne re- 
Quired elevation for miter line of a two-piece angle as called 




397 

for: line ^from c \.o x is miter line, « to x is height of rise, 
and a to r, base line, which is size of diameter called for. 
The line x to a divided into half gives the point r where the 
miter line intersects., of a three-piece angle ; r to « is height, 
a to c is base line, and r to r is miter line, as will be seen by- 
dotted line in drawing. Twice the length of distance of line 
from points a to is the width of outer curve of center see* 
tion. You must, ot course, allow for laps or burrs for join- 
ing same together when cutting pattern. 

Compare this with the solid line center section of full side 
elevation, and see how much quicker this method is over the 
old way. When once accustomed to use this method, you 
will use no other. This rule is absolutely correct for a two 
piece angle, and varies so little on a three-piece angle f^-oni 



Fig. 2 




6eing absolutely correct, as that the variation is practically 
of no moment. 

To develop the stretch-out, Fig. 2, lay out the full length 
of circumference, as is shown in Fig. 2 from a to />, and 
divide this length into six equal parts as in drawing. Make 
the center line. No. 2, same height as required, as in this 
case for the two-piece angle of Fig. 3. Next divide the 
right and left lines nearest to the center line, into four equal 
parts, and mark of one off these parts nearest to the top of 
each line ; .QXid do the same as to s]-)acing to the lines nearest 
to the end 6f stretch-out, as lines No. 4 and ;-, but with the 
difference that you mark off one space at the bottom of each 
line as the drawing fully shows. '>^ntinue the center line 



39^ 

indefinitely downward, and with dividers strike the arc i, 2 
and 3, cutting lines at points i, 2 and 3. Draw line b in- 
definitely upward, reverse the dividers, and with line b as 
center line, draw the arc from point 5 to point 4, cutting 
points 5 and 4; do the same on the other end. Then draw a 
straight line from point 3 to 4, and same from i to r. This 
completes the pattern. Allow for locks or laps on both 
ends, and miter lines, of course. 

The method given above is an old one, but not so uni- 
versally known among tinners as its merits deserve. This 
method is also applicable to develop the pattern for elbow 
as given in Fig. i. I use it for all kinds of elbows. 

TO DRAW ANY OVAL WITH SQUARE AND 
CIRCLE. 



'?^ 




The following is a correct rule to draw any size or oval 
used in the tin shop, with square and circle : 

Draw the line from I to 2, which is the length of the ovak 

Draw line from center to 3, which is one-half the width, and 
draw a line from i to 3. vSet compass from i to center ; 
leave one point on i, and mark 4. Set compass from center 
to 3. Leaveone end (of compass) in cencer and mark 5. Set 
compass from 4 to 5, and Irom 6 draw head lines of circles 7 
and 8, and dot 7 and 8 from points i and 2. Set compass 
from 7 to 7, and mark 9 from 7 7 and 8 8. Complete oval 
Crom 9. 



399 
RAIN WATER STRAINER. 

I hand you a sketch of a rain water strainer which I have 
put up and which gives good results. It is eighteen 
inches high, twelve inches in diameter at the half-circle, five 
and a half inches length of bottom, and five inches deep. 
Allow for all seams. 

A, A^t D^ B'^y By represents the outside of finished 




strainer. K ^^ a section of circular top hinged at .5^ and 
fastened with a turn button. The dotted lines at E show 
the section of circular top, K^ partly open; in is a galvanized 
strainer with three-eighth inch holes. The strainer rests 
upon supports at the ends, and may be removed at will. L 
IS a tin strainer with one-eighth inch holes, and is soldered in 
place. F and G are three-inch inlet and outlet. 2 2 are 
straps on back side, by which the strainer is fastened to the 
building. 

As wiif be seen, the top strainer catches the refuse whicn 
IS washed from the roof and gutters, and is easily taken out; 
the finer particles are C'-ught below and nu^y be removed 
when the top strainer is out. 



4t»o 



OVAL DAMPER, 
inclosed please find method of obtaining an oval damper, 
that when closed in, the pipe will be at an angle of 45°. 

Let A B C D repre- 



sent the pipe, and E F 
the line through the pipe at 
an angle of 45^, which will 
be the position of the damper 
when closed. Divide the 
semi-circle into any even num- 
ber of equal parts, as, i, 2, 3, 
4, etc. (even numbers, because 
in doing so you obtain the 
center line of the short diam- 
eter of the damper). Carry 
lines up until they cut the 
line E F as dotted lines, then 
draw solid lines across, and 
at right angles to the line 
E F, and number them to 
correspond with spaces in 
semi-circle, as I, 2, 3, 4, etc. 
With the dividers step from 
a to I on dotted line, and 
with one point of the dividers 
at a'; cut the solid line I each 
side of the line E. F. Step 
^■"^ • ^ ^ ^ TTTTJu ' fi-oixi b to 2, and with one 
point of the dividers on b^, cut the solid line to both sides of 
the line E F, and so on until all the spaces have been trans- 
ferred. Now set the dividers so as to draw an arc through 
the points 5, 6, 7, both sides of the line E F, and then set 
them to draw the two end circles, as 11, 12, ii, and 1,0, I. 
Draw a' line free hand through the points from I to 5, and 
from 7 to II, both sides of line E F, and you have the re- 
quired damper. y 

The same method is used to obtain the shape of a hole in 
piece of sheet metal that a pipe is to pass through on an 
angle. For instance, let A B C D represent a pipe, and 
E F a roof through which the pipe passes ; we want a piece 
of iron or tin laid on the roof for the pipe to pass through ; 
we want to know how to get the shape of the opening. 
Employ this method and it will give you the required article 




4^1 



A TAPERING ROUND-CORNERED SQUARE 
RESERVOIR. 

' Not long since, there was an inquiry in your columns for 
a pattern for a tapering, round-cornered square reservoir. I 
give herewith diagrams for constructing such a pattern : 

Fig. I is the size, top and bottom (ACFHDBGEis 
the top, and I K N P L J O M is the bottom), and Fig. I 

the upright height. Take the 
perpendicular height a d, Fig. 
I, and mark it off from h to k. 
Fig. 3. Take the radius for 
the corners d C, Fig. I, and 
mark it off from h to i, Fig. 
3, also the radius dK^ mark 
off from K to 1, drawing a line 
from il to cut the line h K, 
which gives the slanting height 
and the radius required for 
striking the corners. Draw the 
lines IK and AC, Fig. 4, the 
same length as I K, Fig. 2, and 
the same distance apart as 1 to i, 
Fig. 3 ; prolong the lines A I 
and C K, Fig. 4, till Ac and 
C d equals to i m, Fig. 3, 
With radius d C, Fig. 4, using 
d and c as centers, strike the 
curves C F and A F, and, with 
a radius d K, Fig. 4, using the same centers, strike the 
curves K N and I M. Take the length of the large quar- 

Eig.. 3. Fig. 4. 



9 




ter-Lircle D H, Fig. 2, and dot off the same distance from 
C to F, Fig. 4; make A E equal to C F. and dravi 



402 

lines from E and F to the centers c and d; draw E G 
and M O at right angles with E c. Take the dis- 
tance from A to C, and make the same distance from 
E to G and M to O, Fig. 3. Draw Ge parallel to E c. 
From G mark off point e, the same length as E to c, then, 
using e as center, strike the curves G B and O J, making the 
curve G B equal to A E ; draw line from B to center c, 
draw B T and J R at right angles to Be, taking the distance 
from B to S, Fig. 2, mark off the same distance from B to 
S and J to R, draw S R parallel with B e, and proceed in the 
same manner with the other end; addmg on the laps, as 
shown, will make the pattern complete in one piece, being 
joined together at R S. 

PATTERN FOR T JOINTS. 

The following rule is a short and explicit method of ob- 
taining a pattern for T joints where different diameters are 
required. Suppose, for instance, a T is required whose diam- 
eters are 3 and 8 inches respectively. 

Divide the stretch-out, a a (which must be the exact 

length required to form up 
3 inches, allowing for 
locks as shown by dotted 
lines) in center as shown 
in the figure. Then 
divide each half equally 
between 6-7 and 7-8 as 
shown by indefinite lines 
2 and 3. Now spread the 
compass to 8 inches, which 
is the diameter of the 
large pipe, set one point 
at 4, and the other <. t 
6; strike a circle to 7; 
then set compass on the 
other line at 5 and draw 
circle 7 to 8. Cut out the circles, and you have your pattern. 
The same rule applies to any diameter by spreading compass 
to the larger diameter and striking the circle on the stretch- 
out required for smaller diameter as shown above. 

Ireland has seventy-six collieries — nine in Ulster, seven 
in Connaught, thirty-one in Leinster, and twenty-nine in 
Munster. Very few of these are being worked. 



^ 










! 
1 
[ 


< 


2 


1 


8 




► 



403 
KOVEL DRAWING INSTRUMENT, 



A pair of dividers, or 
compasses, which will de- 
scribe any figure is shown 
herewith. It is of Eng- 
lish origin and very simple. 
The former, or template 
A, is affixed to one leg, 
and beats against the mid- 
leg B, around which, of 
course, revolves the work- 
ing leg. By this means 
the drawing pen or pencil 
is moved in and out in an 
obvious manner. Speci- 
mens of the work are 
shown in Fig. 2. 




^ The quality of wood is determined by 
spirals. The best has about thirty " crinkles 



the number of 
' in an inch. 




404 

TO DESCRIBE A PATTERN FOR A TAPERING 
SQUARE ARTICLE. 

Erect the Derpendicular line G E ; draw the line A B 

at right angle to 
G E ; make E F 
equal to the slant 
height, and draw 
the line C D par- 
allel to A B; make 
AB equal in 
length to one side 
of the base; make 
CD equal in 
length to one side 
of the top or 
smallest end, draw 
the lines A G and 
B G, cutting the 
point s A C and 
BD, Gas a center 

with the radii G C and G A. Describe the arcs K M and J I ; 

set off on the arc J I, J A, B H and H I equal in length to A B, 

and draw the lines J G, H G, and I G, also the lines J A, B H, 

H I, and K C, D L, L M. 
Edges to be allowed. 

THE PAINTING OF IRON. 

Cast and wrought iron behave very differently under 
atmospheric influences, and require somewhat different treat- 
ment. The decay of iron becomes very marked in certain 
situations, and weakens the metal in direct proportion to the 
depth to which it has penetrated, and, although where the 
metal is in a quantity this is not appreciable, it really becomes 
so when the metal is under three-fourths of an inch in thick- 
ness. The natural surface of cast iron is very much harder 
than the interior, occasioned by its becoming chilled, or by 
its containing a large quantity of silica, and affords an excel- 
lent natural jTotection, but, should this surface be broken, 
rust attacks the metal and soon destroys it. It is very desira- 
ble that the casting be protected as soon after it leaves the 
mold as possible, and a priming coat of paint should be 
applied for this purpose : the other coats thought requisite 
can be given at leisure. Jn considering the painting of 
wrought iron, it must be noticed that, when iron is oxidized 
by contact with the atmosphere, two or three distinct layers 



of scale fotia on the surface, which, unlike the skin upon 
cast iron, can be readily detached by bending or hammering 
the metal. It will be seen that the iron has a tendency to 
rust from the moment it leaves the hammer or rolls, and the 
scale above described must come away. One of the plans to 
])reserve iron has been to coat it with paint when still hot at 
the mill, and, although this answers for a while, it is a very trou- 
blesome method, which iron masters cannot be persuaded to 
adopt, and the subsequent cutting processes to which it is 
submitted leave many parts of the iron bare. Besides, a good 
deal of the scale remains, and, until this has fallen off or been 
removed, any painting over it will be of little value. The 
only effectual way of protecting wrought iron is to effect a 
thorough and chemical cleansing of the surface of the metal 
upon which the paint is to be applied ; that is, it must be 
immersed for three or four hours in water containing from 
one to two per cent, of sulphuric acid. The metal is after* 
ward rinsed in cold water, and, if necessary, scoured with 
sand, put again into the pickle, and then well rinsed. - If it 
is desired to keep iron already cleansed for a short time before 
painting, it is necessary to preserve it in a bath rendered alka- 
line by caustic lime, potash, soda, or their carbonates. Treat- 
ment with caustic lime water is, however, the cheapest and 
most easy method, and iron which has remained in it some 
hom-s will not rust by a slight exposure to dampness. Hav- 
ing obtained a clean surface, the question arises, what paint 
should be used upon iron ? Bituminous paints, as well as 
those containing variable quantities of lard, were formerly 
considered solely available, but their failure was made appar- 
ent when the structure to which they were applied happened 
to be of magnitude, subjected to great inclemency of weather 
or to constant vibration. Recourse has, therefore, been had 
to iron oxide itself, and with satisfactory results. A pound 
of iron oxide paint, when mixed ready for use in the propor- 
tion of two-thirds oxide to one-third linseed oil, with careful 
work, should cover twenty-one square yards of sheet -iron, 
which is more than is obtained with lead compound. 

INVENTOR OF THE SCREW-AUGER. 

The screw-auger was invented by Thomas Garrett about 
)lOO yeai-s ago. He lived near Oxford, Chester County, Pa^ 
The single screw-auger was invented by a Philadelphian, and 
it is said to be the only one used with any satisfaction in very 
hard woods, wh'^re the double screw-augers bec(^,me clothed 



4.o6 



RUST PROOF WRAPPING PAPER. 

This is made by sifting on the sheet of pulp, in process of 
tnanufacture, a metallic zinc powder (blue powder), about to 
the extent of the weight of the dried paper, the pulp sheet 
Is afterward pressed and dried by running thiough the 
rolls and over the drying cylinders as usual. The zinc powder 
adheres to the paper, and is partly incorporated with it, the 
amount varying with the thickness and wetness of the pulp 
sheet. The paper may be sized with glue or starch and then 
dusted with the zinc powder, or the powder may be stirred 
into the size and then applied to the surface of the paper. 
If silver, brass or iron articles are wrapped in paper thus pre- 
pared, the affinity of the zinc for the sulphureted hydrogen 
(always present in the air), chlorine or acid vapors, will pre- 
vent those substances from attacking the articles inclosed in the 
piper. 

HIP-BATH IN TWO PIECES. 

Fig. I. 

Draw the hip-bath 
full size, as it would 
look when finished, 
as in Fig. i . Extend 
line b, or the front, to 
same height as c, the 
highest part of the 
tub. Draw line d 
parallel with ^, or 
bottom of tub, until 
it intersects c and b. 
Strike the half-circle 
f f, and divide into 
any number of equal 
parts, as i, 2, 3, 4, 
etc. (the more lines 
the better). For the 
points draAv lines as 
shown in profile. 

Set dividers same as 
when the circles in 
Fie. I were described, and strike the circles ^ p\ and wdth a 
T square draw the perpendicular lines hhhh. Draw the line 
i parallel with the lines h. Take the height same as from d 
to e, in Fig. I, and mark the line/. Fig. i. Draw lines k k 
until they intersect at /. Set dividers at /, and strike the 




407 

circles m m. Draw line n, and, taking it as the center li»«, 
step each way one-fourth of the circumference, in as mani* 
parts as in profile, I, 2, 3, 4, etc., and draw lines same as iu 
Fig. I. 

Fig. 2. 




Take a pair of dividers, and from the bottom of tub in 
profile step on the lines, as from 9 to 9, 8 to 8, etc., making 
the line in Fig. 2 equal to the hnes in profile, st opining where 
the curved line a crosses. A line traced through the dots 
will give the ]Dattern, is the foot, which is drawn tlie same as 
\he other, with the exception of drawing tl>e lines through. 

A VERY dural)le black paint for out-of-door work, and for 
many other purposes, is made by grinding powdered charcoal 
m linseed oil, with sufficient litharge or drier. Thin for use 
with boiled linseed oil. 



4oS 

ROjeE TRANSMISSION IN ENGLAND. 

According to the London Engineer, a fly-rope apparently 
ft-as first used in England in 1863, by Mr. Ramsbottom, for 
driving cranes at Crewe. These ropes were ^ inch in diam- 
eter when new, of cotton, and weighing i^ ounces per foot. 
They lasted about eight months, and ran at 5,000 per minute. 
The total lengths of the rope were 800 feet, 320 feet and 56G 
feet. The grooves in the pulley were V-shaped, at an angle 
of 30°. The cord was supported every 12 feet or 14 feet by 
flat pieces of chilled cast iron. The actual power strain on 
\he rore was about 17 pounds, and the ropes were kept tight 
by a pull of 109 pounds put on by a jockey pulley. Rope- 
gearing is now superseding belting and gearing in cotton 
mills. It has long been used in South Wales for driving 
helve hammers in tin-plate mills. The ropes are usually 
about 5^ inches to 6^ inches in circumference, of hemp. 
The diameter of the pulleys should be at least 30 times that 
of the rope, and the shafts should not be less than 20 feet 
apart. A 6^-inch rope is about equivalent to a leather belt 
4 inches wide, running at the same speed — 3,000 feet per 
minute. Such a rope will transmit 25 horse-power. The 
coefficient of resistance to slipping of a rope in a groove is 
about four times that of an equivalent belt. 

HEAT-PROOF PAINTS. 

Steam pipes, steam chests, boiler fronts, smoke connec- 
tions and iron cliimneys are often so highly heated that the 
l^'^'int upon them burns, changes color, blisters and often 
flukes off. After long protracted use, under varying circum- 
stances, it has been found that a silica-graphite paint is well 
adapted to overcome these evils. Nothing but boiled linseed 
oH'y required to thin the paint to the desired consistency for 
application, no dryer being necessary. This paint is applied 
in the usual manner with an ordinary brush. The color, of 
course, is black. But another paint, which admits of some 
variety in color, is mixed by making soapstone, in a state of 
fine powder, with a quick drying varnish of great tenacity 
and hardness. This will give the painted object a seemingly 
enameled surface, which is durable, and not aftected by heat, 
acids, or the action of the atmosphere. When applied tc 
wood it prevents rotting, and it arrests disintegration when 
applied to stone. It is well known that the inside of an iron 
ship is much more severely affected by corrosion than the 
outside, and this paint has proven itself to be a most efficient 
protection from inside corrosion. It is lig^ht, of fine grain. 



409 

can be tinted with suitable pigments, spread' easily, and 
takes hold of the fiber of the iron or steel quickly and tena- 
ciously. 

A cheap and effective battery can be made by dissolving 
common soap in boiling water and adding to it small amounts 
of bran and caustic potash or soda. This mixture, while 
warm, is poured in a jar containing a large carbon pole and 
an amalgamated zinc rod. When cold the battery "sets " 
after the manner of a jelly, and consequently will not readily 
evaporate or spill over. 

NEW PROCESS FOR WIRE MANUFACTURE. 

A machine for cheapening and improving steel or iron 
wire has been invented, which is calculated to make a change 
in many branches of industry in which iron, steel, copper 
and brass wire are used. The invention, which has just been 
patented, consists of a series of rolls in a continuous train, 
geared with a common driver, each pair of rolls having a 
greater speed than the pair preceding it, with an intervening 
friction clutch adapted to graduate the speed of the rolls to 
the speed of the wire in process of rolling. The entire pro- 
cess of manufacturing the smallest-sized wires from rods of 
one-half inch is done cold. The new process obviates the 
danger of unequal annealing, and of burning in the furnaces, 
and the wire is claimed to be more flexible and homogeneous 
than that produced by the common processes, and capable of 
sustaining greater longitudinal strain. It is, therefore, 
specially adapted for screws, nails, cables, pianofortes, and 
many other uses, and copper wire made by this process is 
claimed to be possessed of greatly increased electrical con- 
ductivity. 

SLEEPERS USED BY THE WORLD'S RAILROADS. 

According to the Moniteitr Indtistriel^ the six principal 
railways of France use more than 10,000 wooden sleepers pet 
day, or 3,650,000 per annum. As a tree of ordinary dimen* 
sions will only yield ten sleepers, it will be necessary to cnt 
down 1 ,000 trees per day. In the United States the con- 
sumption is much greater, amounting to about 15,000,000 
sleepers per year, which is equivalent to the destruction of 
170,000 acres of forest The annual consumption of sleepers 
by the railways of the world is estimated at 40,000,000. 
From these figures the rapid progress of disforest at ion will 
be understood, and it is certain that the natural growth can* 
not keep pace with it. 



4IO 

WEIGHTS OF CAST IRON PIPES. 

Weights, per foot, of Cast Iron Pipes in general use, 
including Socket and Spigot ends. 



Diameter. 


Thickness 


Weijrht 
per foot. 


Diameter. 


Thickness 


Wcijrht 
per loot. 


Staehcs. 


K+" 


inch. 


6I41I.S. 


14 


nchcs 


% 


inch. 


138 lbs. 


,« 


T" 


% 


" - 


«'^ " 


1 6 


" 


^ 


~« 


85 - 


:.'« 


cA 


^.6 


" 


14 . " 


16 




% 


- 


108 - 


<»■ 


& 


%+ 


:« 


11 ' 


16 




% 


" 


129 • 


: '^ 


«■' 


% 


" 


ISJ^ " 


16 




H 




152 •* 


'4'. 


xS> 


H 


"" 


18 - 


16 




1 




175 • 


'Cs\ 


^ 


•^ 


" 


23 " 


18 




% 




114 - 


i* 


«- 


iJ^8 + 


■m 


16>^ « 


18 




\ 




187 • 


'* 


& 


J6 


u 


23 - 


18 




% 




161 - 


* 


«• 


% 




31- " 


20 




% 




132 • 





«» 


3ff 


" 


26 - 


20 




H 




160 • 


U 


«> 


J6 


„ 


33 ' - 


20 




re 




197 - 


hft 


<« 


!5^ 


•«' 


4 "21^ " 


20 




1 




216 • 


] ■ 


■A 


% 


40 


r»2 - 


24 




■Xs 




159 • 


l« 


v« 


% 


•» 


4» 


24 




% 




100 "^ 


'9 


.ur 


\^ 


" 


433<i " 


24 




vt 




224 " ' 


•-? 


u 


% 


" 


56 «• 


24 




1 




257 - 


S 


- 


'^i 


" 


68 " 


30 




'4 




237 - 


10 


"•' 


/e- 


- 


60 


30 




.K 




27 7 -^ 


10 


- 


>6 


" 


«4 " 


30 




I 




310 * 

1 


10 


u 


% 


- 


68 - 


30 




\% 




360 *. 


10 


k 


?i 


a 


80 " 


36 




% 




332 "^ 


12 


'.•1 


Jv 


- 


67 - 


36 




1 




881.-^ 


12 


" 


51 


M 


82 " 


36 




1^8 




429 -J 


12 





2i 


• 


99 


36 




VA 




470 -1 


12 


» 


% 


" 


117 


48 




1 




612 •! 


14 


" 


J6 


u 


74 « 


48 




1^8 




684 *' 


• 


M 


% 


a 


94 


48 




1^4 




686 • 




M 


% 


M 


113 « 


48 




1J6 




776 ^- 



411 
POINIS FOR BUILDERS. 

BY STEEL SQUARE. 

Never compete with ^ ' botch " if you know he is favored 
by the person about to build. He will undercut and beat 
you every time. 

Favor the man who employs an architect. Under an 
honest architect you will have less friction, make more 
money, be better satisfied v;ith your work, and give greater 
satisfaction to the owner than in working from plans fur- 
nished by a nondescript. 

In tearing down old work, be as careful as putting up 
new. 

Old material should never be destroyed simply because it 
is old. ! 

When putting away old stuff, see that it is protected from 
rain and the atmosphere. 

It costs about fifteen per cent, extra to work up old ma- 
terial, and this fact should be borne in mind, as I have known 
several contractors who paid dearly for their " whistle " in 
estimating on working up second-hand material. 

These remarks apply to woodwork only. In using old 
brick, stone, slate and other miscellaneous materials, it is as 
well to add double price for working up. 

Workmen do not care to handle old material, and justly 
so. It is ruinous to tools, painful to handle, and very de- 
structive to clothing. 

In my experience I always found it pay to advance the 
wages of workmen — skilled mechanics — while working up 
old material. This encouraged the men and spurred them 
to better efforts. 

Sash frames, with sash weights, locks and trim complete, 
may be taken out of old buildings that are being taken down 
and preserved just as good as new by screwing slats and 
braces on them, which not only keep the frame square, but 
prevent the glass from being broken. 

Doors, frames and trims may also be kept in good order 
nntil used, by taking the same precautions as in window 
frames. 

Old scantlings and joists should have all nails drown oi 
hammered in before piling away. 

Counters, shelving, draws and other store-fittings should be 



^12 

kindly dealt with. They will all be called for sooner or 
later. 

Take care of the locks, hinges, bolts, keys, and other hard- 
ware. Each individual piece represents money in a greater or 
less sum. *■ 

Old flooring can seldom be utilized, though I have seen i^ 
used for temporary purposes, such as fencing, covering of 
veranda floors, while finishing work on plastering, etc. As 
a rule, however, it does not pay to take it up carefully and 
preserve it. 

Conductor pipes, metallic cornices, and sheet metal work 
generally can seldom be made available a second time, though 
all is worth caring for, as some parties may use it in repairs. 

Sinks, wash-basins, bath-tubs, traps, heating appliances, 
grates, mantels and hearth-stones should be moved with care. 
They are always worth money and may be used in many 
places as substitutes for more inferior fixings. 

Marble mantels require the most careful handling. 

Perhaps the most difiicult fixtures about a house to adapt a 
second time are the stairs. Yet, I have known where a 
shrewd contractor has so managed to put up new building? 
that the old stairs taken from another building just suited. 
This may have been a " favorable accident," but the initiated 
reader will understand him. Seldom such accidents can 
occur. 

Rails, balusters and newels may be utilized much re-adler 
than stairs, as the rail may be lengthened or shortened to suit 
variable conditions. 

Gas fixtures should be cared for and stowed away in some 
dry place. I'hey can often be made available, and are easily 
renovated if soiled or tarnished. 

It is not wise to employ men to take down buildings who 
who have no other qualities to recommend them than their 
strength. As a rule they are like bears — have more strength 
than knowledge, and the lack of the latter is often an ex- 
pensive desideratum. Employ for taking down the work 
good, careful mechanics, and do not have the work " rushed 
through." Rushers of this sort are expensive. 

Never send old material to a mill to be sawed or planed. 
No matter how carefully nails, pebbles and sand have been 
hunted for, the saw or planer knives will most assuredly 
find some vou overlooked; then there will be trouble at the 
mill. 

Have some mercy for tjie workman's tools. If it can be 
avoided, do not work up old stuff into fine work. If not 



413 

avoidable, pay the workman something extra because of in» 
jury to tools. 

Don't grumble if you do not get as good results from the 
use of old material as from new. The workman has much 
to contend with while working up old, nail-speckled, sand* 
covered material. 

RULES FOR ESTIMATING COST OF PLASTER- 
ING AND STUCCO WORK. 

PLASTERING. 

Plastering is always measured by the square yard for aB 
plain work, and by the foot superficial for all cornices of 
plain members, and by foot lineal for enriched or carved 
moldings in cornices. 

By plain work is meant straight surfaces (like ordinary 
walls and ceilings), without regard to the style or quantity of 
finish piit upon the job. Any paneled work, whether on 
walls or ceilings, run with a mold, would be rated by the 
foot superficial. 

Different methods of valuing plastering find favor m 
different portions of the country. The following general 
rules are believed to be equitable and just to all parties: 

Rule I. — Measure on walls and ceilings the surface 
actually plastered without deducting any grounds or any 
openings of less extent than seven superficial yards. 

Rule 2. — Returns of chimney breasts, pilasters and all 
strips of plastering, less than 12 inches in width, measure as 
12 inches wide; and where the plastering is finished down 
upon the wash-board, surbase or wainscoting, add 6 inches to 
height of wall. 

Rule J. — In closets, add one-half to the measurement ; 
or, if shelves are put up before plastering, charge double 
measurement. Raking ceilings and soffits of stairs, add one- 
half to the measurement. Circular or elhptical work, charge 
two prices ; domes or groined ceilings, three prices. 

Rule 4. — For each 12 feet interior work is done further 
from the ground than the first 12 feet, add five per cent. 
For outside work, add one per cent, for each foot the work 
is done above the first 12 feet. 

STUCCO WORK. 

Rule I, — All moldings, less than one foot girt, to be 
rated as one foot ; over one foot, to be taken superficial. 
When work requires two molds to run same cornice, add 
one-fifth. 



414 

Rule 2. — P'or each internal angle or miter, add one foot 
to length of cornice ; and each external angle add two feet. 
All small sections of cornice less than 12 inches long measure 
as 12 inches. For raking cornices add one-half. Circular or 
elliptical work, double price ; domes and groins, three prices. 

Rule j>. — For enrichments of all kinds, charge an agreed 
price. 

Rule 4. — For each 12 feet above the first 12 feet from 
the ground, add five per cent. 

CHINESE CASH. 

A large number are engaged in molding, casting and fin- 
ishing the " cash " used as coin all over China, Mexican 
dollars and Sycee silver being used in large transactions. The 
cash are made from an alloy of copper and zinc, nearly 
the same as the well-known Munn metal, and it takes 
about 1,000 of them to answer as change for a dollar, so 
minute and low do prices run in this country, of which I will 
only give one instance. The fare for crossing the ferry on the 
Peiho was only two cash, or one-fifth of a cent. 

DEEP SOUNDINGS NEAR THE FRIENDLY 
ISLANDS. 

Her Majesty's surveying ship Egeria, under the com- 
mand of Captain P. Aldrich, R. N., has, during a long 
sounding cruise and search for reported banks to the south of 
the Friendly Islands, obtained two very deep soundings of 
4,295 fathoms and 4,430 fathoms, equal to five Eng- 
lish miles respectively, the latter in latitude 84 deg. 
37 min. S., longitude 175 deg. 8 min. W., the other 
about twelve miles to the southward. These depths 
are more than 1,000 fathoms greater than any before 
obtained in the Southern Hemisphere, and are only 
surpassed, as far as is yet known, in three spots in the 
the world— one of 4,655 fathoms off the northeast coast of 
Japan, found by the United States steamship Tuscarora ; 
one of 4,475 fathoms south of the Ladrone Islands by the 
Challenger ; and one of 4,561 north of Porto Rico, by the 
United States ship Blake. Captain Aldrich's soundings 
were obtained with a Lucas sounding machine and galvan- 
ized wire. The deeper one occupied three hours, and 
was obtained in a considerably confused sea, a specimen 
of the bottom being successfully recovered. Temperature 
of the bottom, 33.7 deg. Fahr. 



423 
SIZE AND WEIGHT OF FLAT-TOP CANS. 

The following table gives the size of the flat top cans and 
the amount of material required when galvanized iron is used 
in their construction. The table shows the net weight per 
can with iron from No. 27 gauge to No. 20 gauge. No al- 
lowance is made for seams, hoops, or solder. 



SIZE CANS. 








WEIGHT PER 


CAN. 














N 


0. 


No. 


No. 


N 


0. 


No. 


N 


0. 


N 


0. 


N 




*rt 






27 


G. 


26 

t/3 


G. 


25 

!/5 


G. 


24 


G. 


23 

t/2 


G. 


22 


G. 


21 


G.. 


'«» 


<J. 





t^ 




ui 




tfl 




t/j 




6 


5^ 


1) u 




N 




^ 

yA 


N 



^ 
a 


N 








5 





/• 


6 


^ 
^ 


N 




^ 

^ 


5 


1 


63/f 


6K 


I 


6 


I 


7 
























2 


^V2 


83X 


2 


2 


2 


4 


























3 


9 


iiK 


2 


13 


3 





























5 


loK 


13K 


3 


13 


4 


2 


4 


6 


4 


14 


5 


7 


5 


15 


6 


9 


7 


t 


5 


ii5^ 


iiK 


3 


13 


4 


2 


4 


6 


4 


14 


5 


7 


5 


15 


6 


9 


7 


6 


6 


iiK 


X3K 


4 


3 


4 


8 


4 


12 


5 


6 


5 


15 


6 


9 


7 


2 


8 


I 


8 


13^ 


13K 


5 


4 


5 


10 


6 





6 


12 


7 


8 


8 


9 


9 




10 


I 


10 


13K 


16K 


6 





6 


7 


6 


14 


7 


12 


8 


9 


9 


7 


10 


5 


II 


9 


15 


15^ 


9 


7 


15 


8 


8 


9 


I 


10 


3 


IT 


5 


12 


7 


^3 


9 


15 


4 


20 


17M 


19K 


9 


8 


10 


2 


10 


13 


12 


3 


13 


8 


^4 


4 


16 


3 


18 


4 


20 


t6 


23 


9 


8 


10 


2 


10 


13 


12 


3 


13 


8 


14 


4 


16 


3 


18 


4 


25 


18 


23 


II 





IT 


12 


12 


8 


14 


I 


15 


II 


17 


4 


18 


13 


21 


2 


30 


18K 


26K 


12 


10 


13 


8 


14 


7 


16 


4 


18 





19 


^3 


21 


10 


23 


II 


35 


18K 


30K 


14 





15 





16 





18 





20 





22 





24 





27 





40 


18K 


34 


15 


9 


16 


10 


^7 


II 


19 


15 


22 


2 


24 


6 


26 


9 


29 


14 


45 


19^ 


35 


16 


10 


17 


13 


19 





21 


6 


23 


12 


26 


2 


28 


8 


32 


I 


50 


20K 


35 


17 


II 


18 


15 


20 


3 


22 


12 


25 


4 


27 


^3 


30 


5 


34 


2 


55 


21K 


36 


18 


14 


20 


6 


21 


10 


24 


3 


26 


7 


29 


12 


32 


7 


36 


8 


60 


22 


37 


20 


3 


21 


10 


23 





25 


15 


28 


12 


31 


10 


34 


8 


38 


13 


65 


22K 


38 


21 


3 


22 


9 


24 


:? 


27 


4 


30 


5 


33 


6 


36 


5 


40 


14 


70 


23 


40 


22 


10 


24 


4 


25 


13 


29 


I 


32 


5 


35 


8 


38 


12 


43 


9 


75 


23K 


40 


23 


3 


24 


14 


26 


9 


29 


13 


33 


2 


36 


7 


39 


13 


44 


13 


0° 


24K 


40 


24 


7 


26 


3 


27 


15 


31 


7 


34 


15 


38 


6 


41 


15 


47 


3 


85 


25 


40 


25 


I 


26 


14 


28 


10 


32 


7 


35 


^3 


39 


6 


43 





48 


5 


90 


24M 


45 


26 


13 


28 


II 


30 


ID 


34 


7 


38 


4 


42 




45 


15 


51 


II 


95 


25 


45 


27 


7 


29 


6 


31 


5 


35 


4 


39 


3 


43 




47 





52 


14 


100 


26 


45 


28 


13 


30 


14 


32 


14 


37 





41 


2 


45 




49" 


6 


55 


9 


125 


27K 


5° . 


33 


8 


35 


15 


38 


5 


43 


2 


47 


H 


52 


II 


57 


7 


64 


10 


150 


29 


52K 


37 


I 


39 


12 


42 


6 


47 


II 


52 


15 


58 




63 


9 


71 


9 


175 


30 


57M 


41 


9 


44 


8 


47 


7 


53 


6 


59 


5 


65 


3 


71 


3 


80 


I 


200 


3o3X 


64 


46 


6 


49 


12 


53 


3 


59 


14 


66 


6 


73 





79 


10 


89 


10 



Mexican coal has been successfully used for makin<r coke 
at Pittsburg. 



4IO 

WEIGHTS, &c., OF MATERIALS. 
Specific Gravity — Weight and Strength of Metals. 





02^ 


Weight of 
1 cubic 
foot. 


Weight of 
1 cubic 
inch. 


Strength per sq. in. 


Metals. 


Ten- 
sile. 


Crush- 
ing. 


Trans- 
verse. 


Piatinum 


21.531 

23.0 

18.417 

13.596 

10.474 

11.36 

11.4 

9.822 

8.85 

8.607 

8.78 

8.9 

7.291 

7.0 

7.0 

7.6 

7.3 

75 

7.8 

7.78 

8.0 

6.72 
2.67 
2.56 

7.68 

8.564 

8.456 

8.397 

7.31 


Ib3. 

1343.9 
1435.6 
1150.0 
848.75 
653.8 
708.5 
711.6 
613.1 
552.4 
537.3 
548.1 
555.0 
455.1 
437.0 
437.0 
474.4 
451.0 
474.4 
486.9 
486.6 

499.0 

419.5 
1666 
159.8 

478.4 

528.36 

527.89 

524.18 

456.32 


lbs. 

.775 

.828 

.665 

.49117 

.377 

.408 

.41 

.353 

.318 

,31 

.316 

.32 

.262 

.252 

.252 

.273 

.26 

.273 

.281 

.28 

.288 

.242 
.096 
,092 

.276 

.306 

.305 

.3 

.263 


tona 

9.1 

18.2 

.8 

1.5 

1.45 

17.0 

8.4 

13.4 

26.0 

2.0 

3.3 

6.0 

13.0 

7.3 

16.0 

29.0 

22.0 

40.0 

52.0 

35.0 

.47 

32.0 
16.1 
13.6 
13.1 


tons 

3.1 

6.7 

36.0 
64.0 
48.0 
16.0 
18.0 
16.9 

150.0 
90.0 

58.0 


tons 


" sheet..... 
Gold, pure 


— 


Mercury 




Silver , 




Lead, cast 





" sheet 

Bismuth 


— 


Copper, bolts 

" cast 

" sheet. 

" wire 

Tin. cast 


— 


Zinc, cast 





Iron, cast, from.... 
" to 

" " average. 
Iron, wrought, from 

" " to... 

" " average 
Iron Wire 


2.0 
3.4 
2.6 
3.0 
5.5 
3.8 


Steel " 





" Plates 





Antimony, cast .... 

Aluminum, sheet., 
cast... 

Aluminum Bronze. 
20 to 95 pr. ct. of 
copper . .... 


— 


Gun-Metal, 10 cop- 
per 1 tin 




Gun-Metal, ;7 cop- 
ner 1 tin 




Brass, cast, 3 cop- 
per, 1 zinc 

White Metal, (Bab- 
bitt's) 


— 



BENZINE. — Benzine gas is nearly three times as heavy 
as air. One cubic foot of benzine gas weighs 0.2 i8i lb.; 
while I lb of gas occupies at ordinary temperature and 
pressure 4.58 cubic feet. The corresponding figures for air 
being 0.08 lb. and 12.29 cubic feet respectively. 



417 



SPECIFIC GRAVITY AND STRENGTH OF TIMBER 



Name. 



Ebony 

Greenheart . . . . 

Teak 

Lancewood . . . . 
Oak, American 

*' English.. 

Mahogany 

Hornbeam 

Ash 

Pitch-pine 

Beech 

Ehii 

Red Pine 

Fir, Larch 

" Riga 



Specific 


Tenacity 


Crushing- 


gravity. 


per 
square inch. 


stress per 
square inch. 




lbs. 


lbs. ■ 


I.18 


— 


18,000 


I 


05 


8,000 


12,000 




98 


15,000 


12,000 




95 


20,000 


7,000 




93 


14,500 


7,700 




93 


15,000 


8,250 




«S 


15,000 


8,200 




76 


15.000 


8,500 




.75 


17,700 


9,000 




.70 


12,000 


6,000 




68 


17,000 


8,500 




.55 


14,000 


10,300 




.54 


10,500 


5,000 




53 


11,000 


5,500 




53 


12.500 


5,300 



A VALUABLE POINT FOR PAPER-MAKERS. 

Iron ir, apt to discolor paper by rusting after it has been 
abraded from the paper-making machinery. Magnetism 
has, therefore, been called in by a German manufacturer to 
clear away the iron specks. A series of magnets are ar- 
ranged in the form of a comb and hung across the stream 
of pulp and water, which, in passing the magnetic teeth of 
the comb, delivers up the iron particles. 



PRECAUTIONS TO BE TAKEN IN USING LIQUID 
FUEL IN FURNACES. 

In lighting up from "all cold," it is as well to open 
the fire door and damper so as to create a draught, and 
thereby drive away any possible explosive mixture of air 
and oil gas which might be present through leaks in the 
oil valves. If possible, blow through with the steam jet 
from an adjacent boiler, then introduce the lighted torch, 
and then (not before) turn on the oil supply. If relighting 
a *• hot" furnace, i. e., that in which the oil has been shut 
off for a time, as, say, during a meal hour, blow through 



4i8 

thoroughly with steam first as a precaution, and proceed as 
before. The great danger to be guarded against is the 
formation of an explosive mixture in a very confined space. 
As a general rule, the lighted torch should be affixed to a 
bent rod, so that the attendant can stand away from the fire 
door. Remember that a Jiame must never be brought to 
the oil, but the oil must always be brought to the Jlame, 
i. e., in oil fuel furnaces, there must first be a flame in the 
furnace, then the oil can be turned on. 

Fetroleu?n. — In carrying petroleum or its products on 
motor-vehicles, never allow the containing vessel to be quite 
full, as petroleum sensibly expands when heated, and unless 
provision is made for this, the tank might be ruptured. 

USEFUL NUMBERS FOR WEIGHf OF IRON. 



^ in. dia. = i lb. per ft. run. 
7/^ in. dia.=2 lbs. per ft. run. 



I ^ in. dia. =4 lbs. per ft. run. 
i^ in. dia. =8 lbs. per ft. run. 
I in. sq. of iron weighs 10 lbs. per yard, or 3.33 lbs. per ft. 
I square foot of iron i inch thick weighs 40 lbs. 
I cubic inch of wrought iron weighs 0.28 lb. 
I cubic inch of cast iron weighs 0.26 lb. 
400 cubic inches of wrought iron weigh i cwt. 
425 cubic inches of cast iron weigh i cwt. 

PAINTWORK. 

It may be useful to know that a gallon of paint will cover 
from 450 to 630 superficial feet of wood. On a well-painted 
surface of iron the gallon will cover 720 feet. In estimating 
painting to old work, the first thing to do is to find out the 
nature of the surface, whether it is porous, rough Oi- smooth, 
hard or soft. The surface of stucco, for example, will take a 
great deal more paint than on of wood, much depending on 
the circumstance whether it has been painted, and what state 
the surface is in. We have known prices tendered for outside 
painting that have been seriously wrong, owing to the want 
of knowing the condition of the stucco work. A correct esti- 
mate of repainting woodwork cannot be made from the quan- 
tities only; a personal examination ought to be made in every 
rase where there is much work to be done . A^ great many 
painters trust to the quantity; the consequence is, nothing is 
allowed to remove old paint, or for scouring, and the stoppmg 
of cracks. 

Then, there is painting and painting. It can be done well 
and artistically, or indifferently, and few trades allow of 
greater scamping. In first-clas^ work, after the first two coats 



:i9 

have been put on, the paint, when dry, should be rubbed 
down with pumice -stone before the finishing coats are put on. 
Inferior painting is so common that it has «■ demoralizing effect 
on painters of the day. The quaUty of the material, especially 
the white lead, has much to do with the permanency. We 
find painting done on old work without any cleaning, stopping 
or even pumicing. A slovenly and inartistic class of grainers 
are also met with, who repaint and regrain on work that 
ought to be well rubbed with pumice-stone or sand-paper be- 
fore the first new coat is l?^id. 

For painting three coats, the following materials are given 
tor lOo superficial feet of new work -. Paint, eight pounds ; 
boiled linseed oil, three pints; spirits of turpentine, one pint; 
the work taking thre men for one day. According to Saxton, 
forty-five yards of first coat, including stopping, will require 
five pounds of white lead, five pounds of putty, one quart of 
oil. The same quantity of each succeeding coat will require 
the same allowance of white lead and oil. The best materials 
will last for seven years, but the ordinary painting seldom lasts 
three. 

THE ANNUAL RING IN TREES. 

I'he annual rings in trees exist as such in all timber grown 
in the temperate zone. Their structure is so different in 
different groups of timber that, from their appearance alone, 
the quality of the timber may be judged to some extent. 
For this purpose the absolute width of the rings, the regu- 
larity in width from year to year and the proportion of spring 
*vood to autumn wood must be taken into account. Spring 
wood is characterized by less substantial elements, the ves- 
sels of thin-walled cells being in greater abundance, while 
autumn wood is formed of cells with thicker walls, which 
appear darker in color. In conifers and deciduous trees the 
annual rings are very distinct, while in trees like the birch, 
linden and maple the distinction is not so marked, because 
the vessels are more evenly distributed. Sometimes the 
gradual change in appearance of the annual ring from spring 
to autumn wood, which is due to the difference in its compo- 
nent elements, is interrupted in such a manner that a. more or 
less pronounced layer of autumn wood can apparently^be 
recognized, which again gradually changes to spring or sum- 
mer wood, and then gradually finishes with the regular autumn 
wood, This irregularity may occur even more than once i;i 
the same ring, and this has led to the notion that the annual 
rings are not a true indication of age; but the ^i^mble or 



/120 

oonnterfeit rings can be distinguished by a practiced eye with. 
the aid of a magnifying glass. These irregularities are due 
to some interruptions of the functions of the tree, caused by 
defoliation, extreme climatic condition or sudden changes of 
temperature. The breadth of the ring depends on the length 
of the period of vegelat ion ; also when the soil is deep and rich, 
and Hght has much influence on the tree, the rings will be 
broader. The amount of light, and the consequent development 
of foliage, is perhaps the most powerful factor in wood forma- 
tions, and it is upon the proper use of this that the forester 
depends for his means of regulating the development and 
quantity of his crop. 

POINTERS FOR ARCHITECTS, BUILDERS AND 
WOOD-WORKERS. 

A box of window-glass contains fifty feet of glass, regard- 
less of size of sheets. 

African teak- wood outlasts any other kind of wood. It 
is the only wood found preserved in Egyptian tombs 4,000 
years old. It shrinks only " on end. " 

It is a common practice in France to coat the beams, the 
joists and the under side of the flooring of buildings with a 
thick coating of lime-wash as a safeguard against fire. It is 
a preventive of prime ignition, although it will not check a 
fire when once under headway. 

Any beam, whether of wood or iron, is as much stronger 
when placed on its edge as when on its side, as the width is 
greater than he thickness. Thus a stick or bar of iron one 
inch by three inches when used as a beam is three times as 
strong when placed on its edge as when on its side. This is 
true only within limits. It would not be true of a piece oi 
boiler-plate, on account of the flexibility. 

Mortar made in the following manner will stand if used in 
ijmost all sorts of weather: One bushel of unslaked lime, 
three bushels of sharp sand ; mix i lb. of alum with one pint 
of linseed oil, and thoroughly mix this with the mortar when 
making it, and use hot. The alum will counteract the action 
of the frost on the mortar. 

A new system of building houses of steel plates is being 
introduced by M. Danly, manager of the Societe des Forges 
de Chateleneau, It has been found that corrugated sheets 
only a millimetre in thickness are sufficiently strong for build- 
ing houses several stories high, and the material used allows 
of architectural ornamentation. The plates used are of the 



421 

finest quality, and as the^ are galvanized after they have been 
cut to the sizes and shapes required, no portion is left 
exposed to the action of the atmosphere. Houses so con- 
structed are very sanitary, and the necessary ventilating and 
heating arrangements can readily be carried out. 

Moisture-proof glue is made by dissolving 16 ounces of 
glue in 3 pints of skim milk. If a still stronger glue be want- 
ed, add powdered lime. 

Shellac and borax boiled in water produces a good stain 
for floors. 

Don't inclose the sink — no place in a kitchen is so 
much neglected. 

Porch floors should be of narrow stuiif and the joints laid 
in white lead. 

Lime-water is fire-proof protection for shingles or any 
light wood-work. 

Common brick absorb a pint of water each, and make a 
very damp house. 

The lowest-priced builder is not always the cheapest^ as 
poor work will testify. 

A closet finished with red cedar shelves and drawers is 
death to moths and insects. 

Do not locate a furnace register next to a mantel —that 
is, if you wish to utilize the heat. 

Terra-cotta flue linings are a great improvement over 
the old, roughly plastered chimney. 

For basement flooring, oak is preferred to maple because 
it will stand dampness better. 

To properly select the colors applicable to the proper 
place, consult an educated painter. 

A ventilating flue from the kitchen into the chimney 
often does away with atmospheric meals. 

Stops to doors and windows should be fastened with 
roundhead screws, so as to be easily moved. 

It is better to oil floors than to paint them — a monthly 
rubbing will make them as good as new. 

Do not use one chimney-flue for two stove pipes — txle 
draft of one will counteract that of the other. 

Do not finish windows to the floor — -the circulation 
across the floor is one of the causes of cold houses. 

Ash-pits in cellars under fire-places and mantels save 
taking up ashes, for they may be raked down through a hop- 
per. 

Do not construct solid doors of two kinds of hardwood 
— the action of the atmosphere on one or the other will 
cause the door to warp. 



422 

HINTS ON VENTILATION. 

In ventilating ^- say, a bed-room — by means of the win* 
dow, what you may principally want is an upward-blowing 
current. Well, there are several methods of securing this 
without danger of a draught. 

1. Holes may be bored in the lower part of the upper 
sash of the window, admitting the outside air. 

2. Right across one foot of the lower sash, but attached 
to the immovable frame of the window, may be hung or tacked 
apiece of strong Willesden paper — prettily painted with 
flowers or birds, if you please. The window may then be 
raised to the extent of the breadth of this paper, and the air 
rushes upward between the two sashes. 

3. The same effect is got from sim.ply having a board 
about six inches wide and the exact size of the sash's breadth. 
Use this to hold the window up. > 

4. This same board may have two bent or elbow tubes in 
it, opening upward and into the room, so that the air 
coming through does not blow directly in. The inside open- 
ings may be protected by valves, and thus the amount of in- 
coming current can be regulated. We thus get a circulating 
movement of the air, as, the window being raised, there is an 
opening between the sashes. 

'v^. In summer a frame half as big as the lower sash may 
be made of perforated zinc or wire gauze and placed in so as 
to keep the window up. There is no draught; and, if kept in 
position all night, then, as a rule, the inmate will enjoy re- 
freshing sleep. 

6. In addition to these plans, the door of every bed- 
room should possess, at the top thereof, a ventilating panel, 
the simplest of all being that formed of wire gauze. 

In conclusion, let me again beg of you to value fresh air 
as you value life and health itself; while taking care not 10 
sleep directly in an appreciable draught, to abjure curtains 
all round the bed. A curtained bed is only a stable for 
nightmares and an hotel for a hundred wonder-ills and ail- 
..^^nts. 

STRENGTH OF ICE. 

Ice two inches thick will bear men to walk on. 

Ice four inches thick will bear horses and riders. 

Ice eight inches ihick will bear teams with very heavy 
loads. 

Ice ten inches thick will sustain a pressure of 1,000 
pounds per square foot. 



423 

THE FORESTS OF THE UNITED STATES. 

The total area of forest lands in the United States and 
Territories, according to the annual report of the Division 
of Forestry of the Department of Agriculture, is 465,795,000 
acres. The State which has the largest share is Texas, 
which is credited with 40,000,000 acres. Minnesota comes 
next with 30,000,000, then Arkansas with 28,000,000; and 
Florida, Oregon, California and Washington Territory are 

put down at 20,000,000 each. Georgia and North Carolina 
have each 18,000,000; Wisconsin and Alabama, each 
17,000,000; Tennessee, 16,000,000; Michigan, 14,000,000; 
and Maine, 12,000,000 acres. Taking the States in groups, 
the six New England States have, in round numbers, 
19,000,000 acres; four Middle States, 18,000,000; nine 
Western States, 80,000,000; four Pacific States, 53,000,000; 
seven Territories, 63,000,000; and fourteen Southern States, 
233,000,000 acres, or almost precisely half of the whole for- 
est area of the country. 

Reviewing the figures given by the department, the 
Tradesman, of Chattanooga, Tenn., makes the following 
instructive comment: "These statistics show that, while the 
process of denudation has been carried on to an unhealthy 
extreme in the Eastern, Middle and a few of the Western 
States, the forest area still remaining in this country is a 
magnificent one. If the estimates of the department are 
approximately correct, the timber lands of the country, 
exclusive of Alaska, cover an area equal to fifteen States the 
size of Pennsylvania. If proper measures are taken to pre- 
vent the rapid and unnecessary destruction of what is left of 
our forest domain, it should be equal to all requirements for 
an indefinite period. It is not yet a case of locking the 
stable after the horse is stolen, and never should be allowed 
to become so. With the adoption the policy of judicious 
tree planting in the prairie States, and a system of State or 
government reservations in the mountainous districts, which 
are the sources of the chief rivers of the country, the evil 
effects which have followed forest denudation in Europe and 
some portions of Asia would never exist here. " 

TO FIND THE WEIGHT OF GRINDSTONES. 

.06363 times square of inches diameter, times thickness 
In inches =^ weight of grindstone in lbs. 

^•1415926 = ratio of diameter to circumference of cirdo 



4^4 

ALTITUDE ABOVE THE SEA-LEVEL OF V^ARX- 
OUS PLACES IN THE UNITED STATES. 



Portland, Me 185 

Concord, N. H 375 

Cleveland, O 645 

Detroit, Mich 595 

Mt. Washington 6,293 

Ann Arbor, Mich 890 

Boston, Mass 82 

Albany, N. Y 75 

NewYork, N. Y 60 

Buffalo, N. Y 580 

Philadelphia, Penn 60 

Pittsburg, Penn 935 

Baltimore, Md 275 

Washington, D. C 92 

Charleston, S. C 27 

Vicksburg, Miss 352 

New Orleans, La 10 

El Paso, Texas SjSsi 



Knoxville, Tenn . . » x.-V>', 

Louisville, Ky ^ /^^g 

Cincinnati, O 480 

Upper portion of cd'-^ 588 

San Francisco, Cal 130 

Indianapolis, Ind 700 

Chicago, 111 581 

Milwaukee, Wis 590 

St. Anthony Falls, Mmn.. 822 

Dubuque, la 1,400 

St. Louis, Mo 480 

Omaha, Neb 1,300 

Lawrence, Kan 803 

Fort Phil Kearney, Wy 6,000 

Yankton, Dak 1,900 

Fort Garland, Colo 8,365 

Salt Lake City, Utah 4,322 

Sacramento, Cal 22 



VALUE OF LEAVES AS PURIFIERS. 
A single tree, through its leaves, is capable of purifying 
the air of the carbonic acid which has been exhaled by a 
dozen individuals, or even a score. A human being exhales, 
in the course of 24 hours, about 100 gallons of carbonic 
acid. According to Boussingault's estimate a single square 
yard of ^leaf surface, countnig both the upper and the 
under sides of the leaves, can, under favorable circum- 
stances, decompose at least a gallon of carbonic acid in a 
day. One hundred square yards of leaf surface then would 
suthce to keep the air pure for one man. bin the leaves of a 
tree of moderate size present a surface of many hundred 
square yards. 



HOW TO POLISH ZINC. 

We have been successful in polishing zinc with the follow- 
ing solution: To 2 quarts of rainwater add 3 oz. powdered 
rotten stone, 2 oz. pumice stone, and 4 oz. oxalic acid Mix 
thoroughly, and let it stand a day or two before using. Stir 
or shake it up when using, and, after using, polish the zinc 
with a dry woolen cloth or chamois skin. The more thor- 
oughly the zinc is rubbed the longer it will stay bright. 



425 
HOW TO MAKE A GOOD FLOOR. 

Nothing attracts the attention of a person wishing to rent 
or purchase a dwelling, store or office, so quickly as a hand- 
some, well-laid floor, and a few suggestions on the eubject, 
though not new, may not be out of place. 

The best floor for the least money can be made of yellow 
pine, if the mateiial is carefully selected and properly laid. 

First, select edge-grain yellow pine, not too "fat," clear 
of pitch, knots, sap and splits. See that it is thoroughly 
seasoned, and that the tongues and grooves exactly match, so 
that, when laid, the upper surfaces of each board are on a 
level. Ihis is an important feature often overlooked, and 
planing-mill operatives frequently get careless in adjusting 
the tonguing and grooving bits. If the edge of a flooring 
board, especially the grooved edge, is higher than the edge 
of the next board, no amount of mechanical ingenuity can 
make a neat floor of them. The upper part of the groove 
will continue to curl upward as long as the floor lasts. 

Supposing, of course, the sleepers, or joists, are properly 
placed the right distance apart, and their upper edges pre- 
cisely on a level, and securely braced, the most important 
part of the job is to "lay" the flooring correctly This 
part of the work is never, or very rarely ever, done nowa- 
days. The system in vogue with carpenters of this day, of 
laying one board at a time, and " blind nailing," is the most 
glaring fraud practiced in any trade. They drive the tongue 
of the board into the groove of the preceding one, by 
pounding on the grooved edge with a naked hammer, mak- 
ing indentations that let in the cold air or noxious gases, if 
it is a bottom floor, and then nail it in place by driving a 
six-penny nail at an angle of about 50^ in the groove. An 
awkward blow or two chips off the upper part of the groove, 
and the last blow, designed to sink the nail-head out of the 
way of the next tongue, splits the lower part of the groove 
to splinters, leaving an unsightly opening. Such nailing 
does not fasten the flooring to the sleepers, and the slanting 
nails very often wedge the board up so that it does not bear 
on the sleeper. We would rather have our flooring in the 
tree standing in the woods than put down that way. 

The proper plan is to begin on one side of the room, lay 
one course of boards with ilie tongue next to, and neatly 
fitted to, the wall (cr studding, if a frame house), and be 
sure the boards are laid perfectly straight from end to end 
of the room and square with the wall. Then nail tliis coursf: 
firrpl- <-o the sleeners, through and throuj-k, one nail near 



426 

each edge of the board on every sleeper, and you are ready 
to begin to lay a floor. Next, fit the ends and lay down 
four or six courses of boards (owing to their width). If the 
boards differ widely in color, as is often the case in pine, do 
not lay two of a widely different color side by side, but 
arrange them so that the deep colors will tone off into the 
lighter ones gradually. Push the tongues into the grooves 
as close as possible, without pounding with a hammer, or, if 
pounding is necessary, take a narrow, short piece of flooring, 
put the tongue in the groove of the outer board, and pound 
gently on the piece, never on the flooring board. Next, 
adjust your clamps on every third sleeper and at every end 
joint, and drive the floor firmly together by means of 
wedges. IDrive the wedges gently at the start, and each one 
equally till the joints all fill up snugly, and then stop, for, if 
driven too tight, the floor will spring up. Never wedge 
directly against the edge of the flooring board, but have a 
short strip with a tongue on it between the wedge and the 
board, so as to leave no bruises. Then fasten the floor to 
the sleepers by driving a flat- headed steel wire nail of suit- 
able size, one inch from either edge of every board, straight 
down into each sleeper. At the end-joints smaller nails may 
be used, two nails in board near the edges, and as far from 
the ends as the thickness of the sleeper will permit. Pro- 
ceed in this manner until the floor is completed, and you 
will have a floor that will remain tight and look well until 
worn out. 

Such minute directions, for so common and simple a job, 
sound silly, but are justifiable from the fact that there are so 
many alleged carpenters who either do not know how or are 
too lazy to lay a floor properly. 

GLUE FOR DAMP PLACES. 

For a strong glue, which will hold in a damp place, the 
following recipe works well : Take of the best and strongest 
glue enough to make a pint when melted. Soak this until 
soft. Pour off the water, as in ordinary glue-making, and 
add a little water if the glue is likely to be too thick. When 
melted, add three table-spoonfuls of boiled linseed oil. Stir 
frequently, and keep up the heat till the oil disappears, 
which may take the whole day, and perhaps more. If 
necessary, add water to make up for that lost by evaporation. 
When no more oil is seen, a tablespoonfulof whiting is added 
and thoroughly incorporated with the glue. 



427 
MORTAR MAKING. 

Much depends on having mortar made on correct, if not 
scientific, principles. The durabiHty, if not the actual safety, 
of a building is more or less affected by the kind of mortar 
that is put into it. We have seen brick buildings, and not 
very old ones either, from which the dry and hardened mor- 
tar could easily be picked in cakes from between the bricks. 
The advantage of using such mortar is, that, when the 
buikling tumbles down, 'there will be no trouble in picking 
from it the old bricks, preparatory to rebuilding. A brick 
wall, if put up with the right kind of mortar, will be solid 
and almost homogeneous, as likely to break through the 
middle of the bricks as at the joints. Such a building will 
never tumble down, except under great strain, and will with- 
stand a pretty severe earthquake shock. 

An old builder, of nearly forty years' experience in mak- 
ing mortar, writing upon the subject to a contemporary, 
very justly says : " The mere matter of slacking lime does 
not make mortar out of it. Lime and water alone will not 
make any better mortar than sand and water." He sug- 
gests the use of plenty of water in slacking the lime, so 
that, when it is run out of the box into the bed, it will not 
bake or burn, as it is liable to do, if not well watered. The 
mortar bed should be large and tignc, so there will be no 
leakage of the lime water. The proportion should be 
about fifty yards of good sand to twenty-five barrels of lime, 
for the first mixing, which should be thoroughly done. The 
hair should be put into the lime before mixing in the sand. 
After the mortar has been mixed in the above proportions 
for ten days or more, if the amount of materials given have 
been used, twenty-five to fifty loads of sand may be added 
and worked in. It is said that the water that rises on a 
bushel of slaked lime, and where plenty of water has been 
used, if removed and put on a sharp sand, will make better 
stone than lime and sand mixed, showing that the water 
should be retained in the sand and lime while it is fresh, and 
that the mortar should be tempered in its own liquor. Of 
course, where smaller quantities are used, the proportion 
should be retained, both at the first mixing and in the sand 
added subsequently. 

A pound of ten-penny cut nails will do as much work as 
two pounds of wire nails. Taking the average of all cut nails, 
they are worth nearly double as much as wire nails, from 
tests made at the Watertown Government Arsenal. 



428 

COST OF EXCAVATING AND HANDLING ROCK. 

The average weight of a cubic yard of sandstone or con^« 
glomerate, in place, is given as 1.8 tons, and of compact 
granite, gneiss, limestone or marble, 2 tons, or an average of 
1.9 tons, or 4,256 pounds. A cubic yard, when broken up 
ready for removal, increases about four-fifths in bulk, and 
/^ of a cubic yard, 177 pounds, is a wheelbarrow load. 
Experience shows that, with wages at $1 per day of 10 
hours, 45 cents per cubic yard is a sufficient allowance for 
loosening hard rock. Soft shales and allied rocks may be 
loosened by pick and plow at a cost of 20 cents to 30 cents 
per cubic yard. The quarrying of ordinary hard rock re- 
quires from ]4. pound to ^ pound and sometimes ^ pound 
of powder per cubic yard. Drilling with a churn driller 
costs from 12 to 18 cents per foot of hole bored. Upon 
these data, Mr. Rigly estimates the total cost, per cubic 
yard of rock in place, for loosening and removing by wheel- 
barrow (labor assumed at $1 per day of 10 hours), as fol- 
lows: When distance removed is 25 feet, total cost=$o.537; 
when 50 feet, $0,549; when 100 feet, $0,573; when 200teet, 
$0,622; when 500 feet, $0,768; when 1,000 feet, $1,011; and 
when 1,800 feet, $1,401. This is exclusive of contractor's 
profit. 

When labor is $1.25 per day, add 25 per cent, to the cost 
prices given; when $1.50 per day, add 50 per cent, and so 
on. In hauling by cart, the cost of loading, which will be 
about 8 cents per cubic yard of rock in place, and the addi- 
tional expense of maintaining the road must be added. 
Allowing, then, 851 pounds as a cart-load, the total cost per 
I ubic yard is estimated, when removed 25 feet, at $0,596; 
when 50 feet*, $0,599; when 100 feet, $0,605; when 200 feet, 
$0,617; when 500 feet, $0,655; when 1,000 feet, $0,717; and 
when 1,800 feet, $0.94. 

IRON BRICK. 

It is reported that the German Government testing labor- 
atory for building materials has reported favorably on a new 
paving-block called iron brick. This brick is made by mix- 
ing ecjual parts of finely-ground day, and adding 5 per cent, 
of iron ore. This mixture is moistened with a solution of 25 
per cent. sul])hate of iron, to which fine iron ore is added 
until it shows a consistency of 38 degrees Baume. It is ther 
formed in a press, dried, dipped once more in a nearly con- 
centrated solution of sul]:)hate of iron and finely ground iron 
ore, and is baked in an oven for 48 hours in an oxidizing 
flame, and 24 hours in a reducing flame- 



429 

DRY ROT IN TIMBER. 

No wood which is liable to damp, or has at any time 
absorbed moisture, and is in contact with stagnant air, so 
that the moisture cannot evaporate, can be considered safe 
from the attack of dry rot. 

Any impervious substance applied to wood, which is not 
thoroughly dry, tends to engender decay ; floors covered 
with kamptulicon and laid over brick arching before the 
latter was dry ; cement dado to wood partition, the water 
expelled from dado in setting, and absorbed by the wood, 
had no means of evaporation. 

Woodwork coated with paint or tar before thoroughly 
dry and well seasoned, is liable to decay, as the moisture is 
imprisoned. 

Skirtings and wall paneling very subject to dry rot, and 
especially window backs, for the space between woodwork 
and the wall is occupied by stagnant air ; the former absorbs 
moisture from the wall (especially if it has been fixed before 
the wall was dry after building), and the paint or varnish 
prevents the moisture from evaporating into the room. 
Skirting, etc., thus form excellent channels for the spread of 
the fungus. 

Plaster seems to be sufficiently porous to allow the 
evaporation of water through it ; hence, probably, the space 
between ceiHng and floor is not so frequently attacked, if 
also the floor boards do not fit very accurately and no oil 
cloth covers the floor. 

Plowed and tongue floors aie disadvantageous in cer- 
tain circumstances, as when placed over a space occupied 
by damp air, as they allow no air to pass between the boards, 
and so dry them. 

Beams may appear sound externally and be rotten 
within, for the outside, being in contact with the air, 
becomes dryer than the interior. It is well, therefore, to 
saw and reverse all large scantling. 

The ends. of all timber, and especially of large beapis, 
should be free (for it is through the ends that moisture 
chiefly evaporates). They should on no account be imbed- 
ded in mortar. 

Inferior and ill-seasoned timber is evidently to be 
avoided. 

Whatever insures dampness and lack of evaporation is 
conducive to dry-rot, that is to say, dampness arising from 
the soil ; dampness arising from walls, especially if the 
damp-proof course has been omitted ; dampness arising 



from use of salt sand ; dampness arising from drying cf mor- 
tar and cement. 

Stagnation of air resulting from air grids getting blocked 
with dirt or being purposely blocked through ignorance. 
Stagnation may exist under a floor although there are grids 
in the opposite walJs, for it is difficult to induce the air to 
move in a horizontal direction without some special means 
of suction. Corners of stagnant air are to be guarded 
against. 

Darkness assists the development of fungus ; whatever 
increases the temperature of the wood and stagnant air 
(within limits) also assists. 

PAINTING FLOORS. 

Colors containing white lead are injurious to wood floors, 
rendering them softer, and more liable to be worn away 
Paints containing mineral colors only, without white lead, 
such as yellow ochre, sienna or Venetian or Indian red, have 
no such tendency to act upon the floor, and may be used with 
safety. This quite agrees with the practice com.mon in this 
country, of painting floors with yellow ochre or raw 
umber or sienna. Although these colors have little body^ 
compared with the white-lead jmint, and need several coats, 
they form an excellent and very durable covering for the 
floor. Where a floor is to be varnished, it is found that var 
nish made by drying lead salts is nearly as injurious as lead 
paint. Instead of this, the borate of manganese should be 
used to dispose the varnish to dry, and a recipe for a good 
floor varnish is given. According to this, two pounds of pure 
white borate of manganese, pounded very fine, are to be 
added, little by little, to a saucepan containing ten pounds of 
linseed oil, which is to be well stirred, and gradually raised to 
a temperature of three hundred and sixty degrees Fahren- 
heit. Meanwhile, heat one hundred pounds linseed oil in a 
boiler until bubbles form ; then add to it slowly the first 
liquid, increase the fire, and allow the whole to cook for 
twenty minutes, and finally remove from the fire, and filter 
while warm through cotton cloth The varnish is then 
ready, and can be used immediately. Two coats should be 
used, and a more brilliant surface may be obtained by a final 
coat of shellac. 



The railroads consume half of the coal used in this country. 



431 

COLD WATER SUPPLY PIPES. 

The following matter, in catechetical form, illustrates 
the teachings of the New York Trades Schools in this con- 
nection : 

I. — What size should the pipe from the street main to 
the house be ? 

A. — The supply pipes of New York average about i/4 to 
I )4 inches in diameter. 

2. — What material is used for this pipe in New York ? 

A. — Mostly lead pipes. 

3. — What other materials, besides lead, are used for sup- 
ply pipes ? 

A. — Galvanized iron, brass, and tin-lined lead pipes. 

4. — How is iron used ? 

A. — Plain, galvanized, and lined with tin or glass. 

5. — What are the advantages and disadvantages of lead 
pipes ? 

A. — Advantages are its ductility, strength, and easiness 
of working, also its durability. Disadvantages are danger 
of poisoning the water, and of being eaten by rats. 

6. — What are the advantages and disadvantages of plain 
iron pipe ? 

A. — Advantages are cheapness, easiness of putting to- 
gether, and freedom from poisoning. Disadvantages are 
rusting, and filling up of pipes. 

7.- What are the advantages and disadvantages of tin- 
lined pipes ? 

A. — Advantage is in its freedom from poisoiJng water. 
Disadvantage in not being durable for hot-water pipes. 

8. — What are the advantages and disadvantages of glass- 
lined pipe ? 

A. — Glass-lined pipe makes an excellent water pipe, but 
is liable to break in working and putting up. 

9. — What are the advantages and disadvantages of gal- 
vanized iron pipe ? 

A. — Galvanized iron pipe is cheap and free from rust, 
but some water decomposes zinc, and its salts are poison- 
ous. 

10.— What are the advantages and disadvantages of 
brass pipe? 

A. — When brass pipe is lined with tin, it is very light 
and strong; but, when the tin wears off, there is danger of 
poisoning the water. 

II. — What are the advantages and disadvantages of 
block-tin pipe ? 



432 

A. — They aiv not durable for hot water, and are very 
expensive. 

12. — What are the advantages and disadvantages of tin- 
lined lead pipe ? 

A. — They are not durable. 

13. — In usimg tin-lined lead pipe, vi^hat must be guarded 
against? 

A. — The lining must not be disturbed or the tin melted 
out. 

14. — How should the supply pipe be connected with 
street mains? 

A. — By a brass tap and coupling. 

15. — How should a lead pipe be joined to an iron piper 

A. — By a brass spud or soldering nipple. 

16. — Should the supply pipe be so arranged that it can 
be emptied? and why? 

A. — Yes. To prevent freezing, and the waterjfrom stag- 
nating in the pipe. 

17. — What precaution can be taken against freezing if 
^he main is within three feet of surface? 

A. — By bending the pipe a few feet lower at the main, 
and continuing the pipe at the lower level. 

18. — In crossing an area with a supply pipe, what precau- 
tion should be taken? 

A. — Cover the pipe with felt, or put it in a box filled with 
saw-dust, to prevent freezing? 

19. — What is gained by putting a supply pipe from street 
main to house in a larger iron pipe? 

A. — The air in a larger iron pipe protects the supply, 
and steam can be injected to thaw pipe if it freezes. 

20. — How can water supply be increased after service 
pipe enters house? 

A. — The flow of water can be greatly assisted by using a 
lar >er pipe after entering the house. 

21. — Is there any way to arrange a pipe so that drawing 
water from a lower floor will not stop or retard the flow 
fro*:a upper floors ? 

A. — The best way would be to proportion branches on 
difterent floors according to pressure ; the smaller the press- 
ure the larger the outlet. 

22. — Suppose a three-story house had a ^ tap from main 
to house, and connected from this tap to top of boiler with 
a iX iiich pipe; what size should the branch pipes to base- 
ment fixtures be ? 

A. — One-half to five-eighths should be large enough. 

23. — The parlor floor contains a pantry sink, a wash- 



433 

basin and a water-closet ; how large should the supply pipe 
from basement to parlor floor be ? 

A. — About I inch in diameter. 

24. — How large the branch pipes to fixtures ? 

A. /^ to ^ in diameter. 

25. — The second floor contains a bath, two water-closets 
and five wash-basins ; how large should the pipe from par- 
lor to second floor be ? 

A. — About I inch in diameter. 

26. — How large should the pipe from basement to tank 
be? 

A. — About 1% inch in diameter. 

27. — In a building of six or more stories in height with 
cold water supply drawn from tank on upper floors, does 
any difficulty occur ? 

A. — Yes. On the lower floors the pressure is to great. 

28. — How can it be remedied ? 

A. — By diminishing branch pipes to give a proportional 
supply. 

29. — Can supply pipe be so arranged that water can be 
drawn from the main or from tank? 

A. — Yes. By using a special stop-cock for the pur- 
pose. 

30. — What precautions should be takf^n to prevent pipes 
freezing ? 

A. — By placing as far from frost as possible, and by 
proper boxing and felting. 

31. — Why are pipes liable to buist when they freeze ? 

A. — The expansion expands the pipes, and, consequently, 
they burst. 

32. — What is the expanding pressure of freezing water ? 

A. — Thirty thousand pounds to the square inch. 

33. — What means are taken to thaw out a service-pipe ? 

A. — The application of heat externally or steam and hot 
water internally is about the best means. 

34.— Is the external application of heat objectionable 
with iron pipes ? 

A. — Yes ; as the sudden contraction is as dangerous as 
the expansion. 

35. — In carrying supply pipes across a floor, what pre- 
caution can be taken to protect ceiling below from a leak ^ 

A. — By puttmg pi]:>es in a box lined with lead, and ha' 
ing a waste, or tell-tale, pipe at lowest ]:)oint. 

36. — Does fresh mortar injure lead pipes ? 

A. — As the iime in fresh mortar is corrosive and forms a 
soluble compound, it is an Mijury to lead pipes. 



434 
PRESSURES ON TANKS. 

Q. — In a full cubical tank, what is the pressure on any 
giertical side ? 

A. — One-half the weight of the contents. 
Q.— In a full conical vessel standing on its base, what is 
the pressure on the base ? 

A. — Three times the weight of the contents. 
Q. — In a hollow sphere, lull of liquid, which is the press- 
ur.^ on the surface of the lower half? 

A. — Three tim^s the weight of contents. 

TINNING BY SIMPLE IMMERSION. 

Argentine is a name given to tin precipitated by gal- 
vanic action from its solution. This material is usually ob- 
tained by immersing plates of zinc in a solution of tin, con- 
taining 6 grammes (about 90 grains) of the metal to the litre 
(0.88). In this way tin scrap can be utilized. To apply the 
argentine according to M. P. Marino's process, a bath 
prepared from argentine and acid tartrate of potash, ren- 
dered soluble by boric acid. Pyrophosphate of soda, chlo- 
ride of ammonium, or caustic soda may be substituted for the 
acid tartrate. The bath being prepared, the objects to b( 
coated are plunged therein, first having been suitably pickled 
and scoured, and they may be subjected to the action of an 
electric current. But a simple immersion is enough. Th( 
bath for this must be brought to ebullition, and the object' 
of copper or brass, or coated therewith, may be immersed 
in it. 

HOW TO FIND THE AMOUNT OF STEAM-PIPE 
REQUIRED TO HEAT A BUILDING WITH 
STEAM. 

Rule for finding the superficial feet of steam-pipe requirec 
to heat any building with steam : One superficial foot o 
steam-pipe to six superficial feet of glass in the windows, oi 
one superficial foot of steam-pipe for every hundred squar( 
feet of wall, roof or ceiling, or one square foot of steam-pipt 
to eighty cubic feet of space. One cubic foot of boiler i; 
required for every fifteen hundred cubic feet of space to b( 
warmed. One horse-power boiler is sufficient for fort) 
thousand cubic feet of space Five cubic feet of steam, a 
seventy-five pounds pressure to the square inch, weighs one 
pound avoirdupois. 



435 

SEASONING TIMBER. 
Timber, when freshly cut, contains from thirty-seven to 
orty-eight per cent, of water, the kind, the age, and the 
eason of vegetation go t/cning the percentage. Older ^/ood 
generally heavier thai young wood, and the weight of 
ood cut m the active season is greater than that of wood 
ut m the dormant season. Water in wood is not chemically 
ombmed with the fiber, and, when exposed to the atmos- 
here, the moisture eva^ orates. The wood becomes lighter 
ntil a certain point is reached in the drying-out process. 
Iter which it gains or loses in the weight according to the 
ariations in the moisture and temperature of the atmos- 
phere. Following is a table showing the percentage in 
weight of water in round woods from young trees at different 
mgths of time after cutting: 

indofWood. 6mos. la mos. i8 mos. 24 mos. 

^^S^ 30.44 23.46 1:8.60 19.95. 

l^^'l 32.71 26.74 z^.zs 20.28 

[ornbeam 27.19 23.08 20.6v> 18.59 

^^^^ 39.72 29.-01 22.73 19.52 

pPlar 40.45 26.22 17.77 17.92 

}^ 33^7^ 16.87 15.21 18.00 

"^^, 41.70 18.67 15.63 17.42 

According to these figures, taken from actual trials, there 
nothing gained by keeping wood longer than eighteen 
onths, so far as drying or seasoning is concerned. In the 
oods mentioned, there appears to be an actual loss in 
►me, and only a slow gain in others after that length of 
me. The pine, fir, and beech gained moisture, and the 
hers in the list lost only very slightly after the eighteen 
onths had passed. 

PROPOSED GREAT ENGINEERING FEAT. 

A gigantic scheme has been proposed, by which the can- 
is of the Rocky Mountains are to be dammed up from the 
madian boundary to Mexico, in order to form vast reser- 
>iis of water to be used in the irrigation of arid lands, and so 
e.ent floods in the lower Mississippi. Major Powell, direc- 
r of the national survey, estimates that at least 150,000 
uare miles of land might thus be reclaimed — a territory 
ceeding in extent one-half of the land now cultivated in the 
mted States. The plan is to build dams across all the can- 
s in the mountains large enough and strong enough to hold 
ck tlie floods from heavy rains and melting snows, and then 

the water down as it may be needed upon the land to be 
:laimpc\ 



43^ 

ON THE USE OF GLUE. 

In order to use glue successfully, says a writer of experi- 
ence, a great deal of experience is required, and it is useless 
for the amateur to try it; he will only spoil the work. So, 
unless the workman is well experienced in the treatment 
and the application of the glue, he had better leave it alone 
entirely. To render the operation successful, two consider- 
ations must t)e taken into account: First, to do good glu- 
ing requires that the timber be well seasoned and thoroughly 
dry, taking care that the joints to be glued are well fitted. 
Second, hi preparing the parts to be glued, each piece should 
he scratched with a sharp file or piece of a fine saw, to 
imake the glue hold better. The shop should be kept at a 
proper temperature, and the material heated so that the 
glue may flow quite freely. Having the glue properly pre- 
pared, spread it evenly upon the parts so as to fill up the 
pores and grain of the wood, then put the pieces together 
as rapidly as possible, using clamps and thumb-screws to 
draw the joints tightly together ; all superfluous glue should 
be washed off", taking great care not to use too much water^ 
or allowing any, to remain on the pieces put together. The 
greatest cause of bad gluing is in using inferior glue and 
in laying it on unevenly. Before using a new brand of glue 
it is safer to test it by gluing a piece of whitewood and 
ash together, clamping it with a thumb-screw, and, when 
dry, insert a chisel where it is put together, and, if the joint 
separates where it is glued, it is not fit to use, and should be 
rejected at once. The wood should split or give way rather 
than the substance promoting adhesion. This is a practi- 
cal and severe test, but it will pay to apply it, in the sta- 
bility of the work. 

GLUE PAINT FOR KITCHEN FLOOR. 

For a kitchen floor, especially one that is rough and 
uufiven, the following glue paint is recommended : To three 
pounds of spruce yellow add one pound, or two pounds if 
desired, of dry white lead, and mix well together. Dissolve 
two ounces of glue in one quart of water, stirring often until 
smooth and nearly boiling. Thicken the glue water after the 
manner of mush, nntil it will spread smoothly upon the floor. 
Use a common paint brush and apply hot. This will fill all 
crevices of a rough floor. It will dry soon, and when dry 
apply boiled linseed oil with a clean brush. In a few hours 
it will be found dry enough to use by laying papers or mats to 
Stsp fi"^./or a few days. When it needs cleaning, use hot suds. 



437 

EFFECT OF THE ATMOSPHERE ON BRICKS. 

Atmospheric influence upon bricks, tiles and other build- 
ing materials obtained by the burning of plastic clays, 
depends very much on the chemical composition of the 
clays and on the degree of burning. Thus, any distinct por- 
tions of limestone present in them would be converted 
into quicklime in the kiln, and, when the bricks were thor- 
oughly wetted, would expand in such a manner as to disin- 
tegrate the mass. If the clay used is too poor — that is to 
say, if it contains an excess of sand — the bricks will not 
become sufficiently fused, and, upon exposure to the weather, 
their constituent parts will separate. It is to be observed 
that in bricks, as in stones, decomposition does not take 
place with the greatest rapidity where constant moisture 
exists, but rather where, from the absence of capillarity, 
variable according to the moisture furnished by the atmos- 
phere, either directly or indirectly, a series of alternatiGS.a 
of dryness and humidity prevail. 

The foundation walls of buildings do not iii fact suffer so 
much in the parts immediately upon the ground as they do 
in those at a height of from one to three feet, according to the 
permeability of the materials employed. When bricks 
made of clay containing free silica are laid in mortar, and 
moisture can pass freely from either one or the other, it 
may be observed that the edges in contact become harder 
than the body of the bricks. No doubt this arises from 
the formation of a silicate of lime and alumina, the lime 
being furnished by the passage of the water through the bed 
of the mortar. 

THE GREAT EIFFEL TOWER. 

One of the principal features of interest at the Paris 
Expositions is the Eiffel tower. [It is constructed of iron, 
and rises to a height of 984 feet. As the greatest height 
yet reached in any structure is that of the Washington 
monument, 550 feet, some idea can be formed of the great 
distance upward that this tower rises. This tow^er weighs 
7,000 tons, and cost 4,500,000 francs. One object of its 
construction is to light the Exposition grounds. The tower 
is supplied with elevators landing the passengers 971 feet 
from the earth. ' It is also supplied with electric lights of 
19,000,000 candle power. Four such towers, with a capacity 
of 50,000,000 each, it is thought, would light the whole 
city of Paris. Perhaps this tower will decide the question 
whether or not it is possible to light an entire city from a 
few points, if not from one. 



ROT IN TIMBER. 

The principal cause of the lack of proper durability of 
timber in buildings is the porosity of the lumber used and 
the consequent liability to absorb moisture. Coarse-grained 
woods of quick growth are more liable to this defect than 
those of tough fiber and slow growth. When timber be- 
comes repeatedly wet and dry, it becomes brittle and weak- 
ened, or "its nature is gone," as the workmen say. Rot is 
of two kinds, wet and dry, and moisture is the essential 
element in both cases, the only difference being that in the 
first the moisture is quickly evaporated by exposure to the 
air, and in the latter, when there is no exposure, it produces 
6. species of fungus and minute worms which eat in between 
the fibers, and gradually produce disintegration. Sap wood 
is more perishable than heart wood, for the former contains 
more of the saccharine principle, and renders the wood liable 
to a fermentive action. 

The prevalent practice of confining unseasoned timber by 
building it close into walls, thus preventing the ready evap- 
oration of whatever moisture happens to get to it, is a bad 
one. The ends of the wood, especially, should be sur- 
rounded by an open-air space, however small, as it is the ends 
where the dampness is most liable to penetrate into the 
structure of the wood. It is a well-known fact that a log of 
green timber, when kept immersed, w^ill become water-logged 
and sink, and, of course, become unfit for use afterward. 
The same process, only slower, applies when it is exposed 
to damp with no facilities for rapid evaporation. Quick- 
lime, when assisted by moisture, is a powerful aid in hasten- 
ing decomposition, in consequence of its affinity for carbon. 
Mild lime has not this effect, but mortar, as used in build- 
ings, requires a considerable length of time to become inert 
in its action as a corroding agent ; therefore bedding timber 
in damp mortar is very injurious, and often the cause of un- 
accountable decay. Wood, in a dry state, does not seem to 
be injured by contact with dry lime, it being rather a preser- 
vative. An example of this is shown in lathing covered with 
plaster, which often retains its original strength when sur- 
rounding timbers are completely rotted away. 

Anything that will hinder the absorbing process will ex- 
tend the life of a wood, such as a coating of tar, paint, or a 
charring of the surface. The latter method will prove the 
most effective, if sufficiently deep, as the charred coating is 
practically indestructible, closes the pores of the wood, and 
will prevent the bursting into flame in case of a fire. If all 



439 



joists, girders and inside beams of every kind were treated 
to a superficial charring process, it would tend, in conjunc- 
tion with fire-proof paint applied to outside finishing work, 
to make a building as nearly fire-proof as wood in any con- 
dition will allow. 



NUMBER OF BRICKS REQUIRED TO 
CONSTRUCT A BUILDING. 



Superficial 


Number of Bricks to Thickness c 


f 


feet of 
Wall. 














4 Inch 


8 Inch 


12 Inch' 


16 Inch 


20 Inch 


24 Inch 


I 


7 


15 


22 


29 


37 


45 


2 


15 


30 


45 


60 


75 


90 


3 


23 


45 


68 


90 


113 


135 


4 


30 


60 


90 


I20 


'§? 


180 




38 


75 


113 


'¥" 


188 


225 


5 


45 


90 


135 


180 


225 


270 


7 


53 


105 


158 


210 


263 


360 


8 


60 


120 


180 


240 


300 


9 


6S 


135 


203 


270 


33^ 


405 


ID 


75 


150 


225 


300 


375 


450 


20 


150 


300 


450 


600 


750 


900 


30 


225 


450 


675 


900 


1,125 


1,350 


40 


300 


600 


900 


1,200 


1,500 


1,800 


50 


375 


750 


1,125 


1,500 


1.875 


2,250 


60 


450 


900 


1,350 


1,800 


2,250 


2,700 


70 


525 


1,050 


1,575 


2,100 


2,625 


3.150 
3,600 


80 


600 


1,200 


1,800 


2,400 


3,000 


90 


67s 


1.350 


2,025 


2,700 


3,375 


4,050 


100 


750 


1,500 


2,250 


3,000 


3.750 


4,500 


200 


1,500 


3,000 


4,500 


6,000 


7,500 


1 9,000 


300 


2,250 


4,500 


6,750 


9,000 


11,25c 


1 T3'5oo 


400 


3,000 


6,ooc 


9,000 


12,000 


15,000 


iS,ooo 

1 n 



Sycamore is being introduced quite extensively for interior 
finish rsWhen properly selected it makes a very handsome 
finish Care should be taken in securing it, ns it is nearly as 
oad to warp as elm. It should be well backed with pir^. 
spruce or hemlock. 



44^ 
FIRE-PROOFING WOODWORK. 

A door of the right construction to resist fire should be 
made of good pine, and should be of two or more thicknesses 
of matched boards nailed across each other, either at right 
angles or at forty-five degrees. If the doorway be more 
than seven feet by four feet, it v^^ould be better to use three 
thicknesses of same stuff; in other w^ords, the door should 
be of a thickness proportioned to its area. Such a door 
should always be made to shut into a rabbet, or flush with 
the wall when practicable ; or, if it is a slide door, then it 
should be made to shut into or behind a jamb, which would 
press it up against the wall. Both sides of the door and its 
(ambs, if of wood, should then be sheathed with tin, the 
Tplates being locked at joints, and securely nailed under the 
locking with nails at least one inch long. No air spaces 
f^'iiould be left in a door by paneling or otherwise, as the door 
vVill resist best that has the most solid material in it. In 
?nost places it is much better to fit the door upon inclined 
metal sliders than upon hinges. 

This kind of door maybe fitted with automatic appliances, 
so that it will close of itself when subjected to the heat of a 
fire ; but these appliances do not interfere with the ordinary 
methods of opening and shutting the door. They only 
constitute a safegard against negligence. 

Under this heading may be classed all the doors of iron, 
whether sheet, plate, cast or rolled, single, double or hollow, 
plain or corrugated, none of which are capable of resisting 
fire for any length of time ; also wooden doors covered with 
tin on one side only, or covered with zinc, which melts at 
700 degrees Fahrenheit, 

The wooden door covered with tin only serves its pur- 
pose when the wood is wholly encased in tin, put on in such 
a way that no air, or the minimum of air, can reach the 
wood when it is exposed to the heat of a fire. Under these 
conditions, the surface of the wood is converted into char- 
coal ; charcoal being a non-conductor of heat, itself tends to 
tetard the further combustion of the wood. But, if air 
penetrates the tin casing in any measure, the charcoal first 
made, and then the wood itself, are both consumed, and the 
door is destroyed. In like manner, if a door is tinned only 
only on one side, as soon as the heat suffices to convert the 
surface of the wood under the tin and next to the fire into 
charcoal, the oxygen reaches it from the outside, and the 
door is of little m )re value than a thin door of iron, or plain 
wooden door. 



441 

DIMENSIONS OF THE MO.^T IMPORTANT OF 
THE GREAT CATHEDRALS. 

Length, Breadth, Height, 

feet. feet. feet. 

St. Peter's , 613 450 438 

St. Paul's 500 248 404 

Duomo 555 240 375 

Notre Dame 416 153 298 

Cologne 444 283 

Toledo 3q5 178 

Rheims 480 163 I17 

Rouen 469 146 465 

Chartres 430 150 373 

Antwerp . 384 171 402 

Strasbourg 525 195 465 

Milan 477 186 360 

Canterbury 530 154 235 

York 524 261 

Winchester.. 554 208 

Durham 411 170 214 

Ely 617 178 

Salisbury 473 229 279 

SUGGESTIONS FOR COLORS. 
In forms, tints, and colors the ocean depths supply valu- 
able decorative suggestions. On silverware the iridescent 
hues of tropical shells are skillfully reproduced, and on 
ceramic ware their fascinating combinations of tints and the 

gradations of these shells have been too much hidden away in 
cabinets, instead of being studied by designers for their ele- 
gant curvatures and attractive colors. The delicate and 
varied hues of the sea anemone, and the curves, volutes and 
flowing lines of the univalves and bivalves are worthy of 
patient study with reference to graceful and fanciful orna- 
mentation. 

REMOVAL OF OLD VARNISH. 
A Mr. Myer has just patented, in Germany, a composi- 
tion for removing old varnish from objects. It is obtained 
by mixing five parts of 36 per cent, silicate of potash, one of 
40 per cent, soda lye, and one of sal ammoniac (hydrochlor- 
ate of ammonia). 



442 



DECIMAL EQUIVALENTS OF INCHES, FEET AND YARDS. 


Frac. Dec. Dec. 


Ins. Feet. 


Yds. 


^f an of an of a 


I = .0833 = 


0277 


Inch. Inch. Foot. 


2 = 


1666 = 


0555 


1-16 = .0625 = .00521 


3 = 


25 = . 


0833 


}i = .125 = .01041 


4 = 


3333 = 


nil 


3-i6= .1875 = .01562 


5 = 


4166 = 


1389 


X = .25 = .02083 


6 = 


5 = 


1666 


5-16 = .3125 = .02604 


7 = 


5833 = 


1944 


Vs = -375 = .03125 


8 = 


.666 = 


2222 


7-16 = .4375 = .03645 


9 = 


75 = 


25 


}4 = .5 = -04166 


10 = 


8333 = 


2778 


9-16= .5625 = 04688 


II = 


9166 = 


3055 


^ = .625 == .05208 


12 = I. = 


3333 


11-16 = .6875 = .05729 






^ = .75 =.06250 






13-16 = .8125 = .06771 






H = .875 = .07291 







DECIMAL EQUIVALENTS OF OUNCES AND POUNDS. 



Oz. Lbs. 


Oz. Lbs. 


Oz. Lbs. 


X = -015625 


4 = .25 


8j4 = -5313 


/z = .03125 


4)4 = .2813 


9 = -5625 


X = .046875 


5 = .3125 


10 = .625 


I = .0625 


5)4 = .3438 


II =.6875 


1)4 = .09375 


6 = -375 


12 = .75 


2 =.125 


6)4 = .4063 


13 = .8125 


2X = -15625 


7 = .4375 


14 = .875 


3 =-1875 


7/2 =^ .4688 . 


15 = -9375 


3'A = -21875 


8 =.5 


16 = I. 



NOTES ON THE LAW AFFECTING ARCHI- 
TECTS. 

A person followmg the occupation of forming plans, draw- 
ings and specifications for building purposes, representing 
himself as an architect, is presumed in law not only as being 
such, but to be learned in the profession. 

If there is any obscurity in the drawings and specifications, 
the contractor should apply to the architect for directions, or 
be liable for the consequences. 

There is no fixed rule as to compensation of architects in 
the United States law. / 

The architect's contract does not survive to his represent- 
ative. So, if there is a contract to complete certain work 



443 

for acertain sum, the representative of a deceased architect 
cannot recover for the part performance. 

In competitions it should always be made clearly under- 
stood that the drawings, etc., are subject to approval, for 
otherwise the party receiving them will be liable tor ttieir 
value, whether used or not. 

An architect has not the right to substitute another per. 

son in his stead. . . -, r ^ • 

If the architect fraudulentlv or capriciously refuses to give 
proper certificates when required, the builder may maintain 
an action for specific performance or against the architect for 
damages. 

PRESERVATION OF WOOD BY LIME. 

I have for many years been in the habit of preparing 
home-grown timber of the inferior sort of fir — Scotch spruce 
and silver — by steeping: it in a tank (that is, a hole dug m 
clay or peat, which was fairly water-tight/ mi a saturated solu- 
tion of lime. Its effect on the sap-wood is to so harden it 
and fill it with pores that it perfectly resists the attacks of the 
little wood-boring beetle, and makes it, in fact, equally as dura- 
ble as the made wood. I had a mill which was lofted with 
Scotch fir prepared in this way in 1850, and it is in perfect 
preservation. The timber is packed as closely as it will he in the 
tank, water is let in, and unslacked lime is thrown on the top 
and well stirred about. There is no danger that the solution 
will not find its way to everything in the tank I leave the 
wood in the solution for two or three months, by the end ot 
which tim_e an inch board will be fully permeated by it. J oists 
and beams would, of course, take a longer time for saturation ; 
but, in practice, we find that the protection afforded by two 
or three months' steeping is sufficient, if the scantlings are cut 
to the sizes at which they are to be used. 

A VERY DURABLE WOOD. 

The interesting fact is stated that so indestructible by 
wear or decay is the African teak wood that vessels built of it 
have lasted one hundred years, to be then only broken up 
b-ecause of their poor sailing qualities from faulty models. 
The wood, in fact, is one of the most remarkab e known, on 
account of its very great weight, hardness and durability its 
weight varying from forty-two to fifty-two pounds per cubic 
foot It works easily, but, on account of the large quantity 
of silex contained in it, the tools employed are quickly worn 
away It also contains oil, which prevents spikes and other 
iron work, with which it comes in contact, from riistmg. 



444 

HOW TO BUILD AN ICE HOUSE. 

I. The ice house floor should be above the level of the 
ground, or, at least, should be above some neighboring area 
to give ail outfall for a drain, put in such a way as to keep 
the floor clear of standing water. 

2. The walls should be hollow. A four inch lining-wall, 
tied to the outer wall with hoop iron, and with a three-inch 
air space, would answer ; but it w^ould be better, if the air 
space is thoroughly drained, to fill it with mineral wool, or 
some similar substance, to prevent the movement of the air 
entangled in the fibers, and thus check the transference by 
convection of heat from the outside of the lining wall. 

3. A roof of thick plank will keep out heat far better 
than one of thin boards with an air space under it. 

4. Shingles will be much better for roofing than slate. 

5. It is best to ventilate the upper portion of the build- 
ing. If no ventilation is provided, the confined air under 
the roof becomes intensely heated in summer ; and outlets 
should be provided, at the highest part, with inlets at con- 
venient points, to keep the temperature of the air over the 
ice at least down to that of the exterior atmosphere. 

TESTING EXTERIOR STAINS. 

Since the use of stains for exterior w^ork became so gen- 
eral, several stains, some good and some bad, have appearrd 
on the market, so that a few points on estimating their com- 
parative values may not be amiss. 

The nose, and, to a less degree, the eye, are admirable 
allies for this work, but, unassisted, are not infallible. The 
following is about the simplest method of testing : 

1. S:^arch for kerosene by warming, and then noting the 
smell. AlsD, note the thinness and lack of covering power 
which, kerosene causes. Kerosene is simply a cheapener. 

2. See how fine it brushes out on a smooth shingle. 
There should not be the slightest grit or any perceptible 
grains of pigment, the presence of w4iich will prove that the 
coloring was mixed dry with the vehicle, and Avas never 
ground fine. 

3. Pour out some of the stain in a tumbler. If it begins 
to settle at once, except in the case of a chrome yellow or 
gi'een, it is made as above stated, by mixing a dry paint with 
the vehicle, and therefore should be avoided. 

A well-ground oil stain tested in this way held up a whole 
day, and a creosote stain a day and a half. 

Of course, when debating between two -tains, it is best 



445 

to try them side by side. In such case the comparative color- 
strength may be determined by diluting equal quantities of 
both stains at about the same shade, with equal quantities of 
turpentine, and then applying the diluted colors to wood, and 
noting the depth of the color. One part of stain to ten parts 
of turpentine is a good strength. 

HOW TO PREPARE CALCIMINE. 

Soak one pound of white glue over night; then dissolve 
it in boiling water, and add twenty pounds of Paris white, 
diluting with water until the mixture is of the consistency 
of rich milk. To this any tint can be given that is de- 
sired. 

Lilac — Add to the calcimine two parts of Prussian blue 
and one of vermilion, stirring thoroughly, and takmg care to 
avoid too high a color. 

Gray — Raw umber, with a trifling amount of lamjv 
black. 

Rose — Three parts of vermilion and one of red lead, 
added in very small quantities until a delicate shade is pro* 
duced. 

Lavendej" — Mix a light blue, and tint it slightly with 
vermilion. 

Stra^v — Chrome yellow, with a touch of Spanish brown. 

Buff^'liyNO parts spruce, or Indian yellow, and one part 
burnt sienna. 

HOW BASSWOOD MOLDINGS ARE MADE. 

Basswood may be enormously compressed, after which it 
may be steamed and expanded to its original volume. Advan- 
tage has been taken of this principle in the manufacture of 
certain kinds of moldings. The portions of the wood to be 
left in relief are first compressed or pushed down by suitable 
dies below the general level of the board, then the board is 
planed dov/n to a level surface, and afterward steamed. The 
compressed portions of the board are expanded by the steam^ 
:o that they stand out in relief. 

BUILDING BLOCKS MADE OF CORNCOBS. 

Buikling blocks made of corncobs form the object of a 
new Italian patent. The cobs are pressed by machinery into 
forms similar to bricks, and held together by wire. They are 
mad ^ Avater-tight by soaking with tar. These molds are very 
hard ctnd strong. Their weight is less than one-third of that 
c^f hollow brick, and they can never get damp. 



446 

REDWOOD FINISH. 
The following formula and directions have been highly 
recommended. 

Take one quart spirits turpentme. 

Add one pound corn starch. 

Add % " burnt sienna. 

Add one tablespoonful raw linseed oil. 

Add ** '' brown Japan. 

Mix thoroughly, apply with a brush, let it stand say fif- 
teen minutes; rub off all you can with fine shavings or a soft 
rag, then let it stand at least twenty-four hours ^ that it may 
sink into and harden the fibers of the wood; afterward apply 
two coats of white shellac, rub down well with fine flint 
paper, then put on from two to five coats best polishing var- 
nish; after it is well dried, rub with water and pumice-stone 
gi-ound very fine, stand a day to dry; after being washed 
clean with chamois, rub with water and rotten-stone; dry, 
wash as before clean, and rub with olive oil unti] dry. 

Some use cork for sand-papering and polishing, but a 
smooth block of hard wood, like maple, is better. When 
treated in this way, redwood will be found the peer of any 
wood for real beauty and life as a house trim or finish. 

A NEW WALL PLASTER. 

A new material for use instead of common plaster is ow 
prepared, which offers many advantages, as it can be app..ed 
more quickly, and dries in less than twenty-four hours. It 
is impervious to dampness, and there is no possibility of the 
window and door casings contracting or swelling and causing 
cracks, as very little water is required in the mixing. It is 
known as "Adamant " wall-plaster, and deserves its name, as, 
when once dry, it is very hard to break. From a sanitary 
point of view, it is also valuable, as it is non-absorbent. 

A RELIABLE CEMENT. 

A reliable cement, one that will resist the action o! 
water and acids, especially acetic acid, is : Finely powdered 
litharge, fine, dry white sand and plaster of Paris — each 
three quarts by measure — finely pulverized resin one part. 
Mix and make into a paste with boiled linseed oil, to which 
a little dryer has been added, and let it stand for four or five 
hours before using. After fifteen hours' standing, it loses 
Strength. The cement is said to have been successfully used 
in Zoological Gardens, London. 



44/ 

PAVEMENTS. 

Bricks, impregnated at a warm temperature with as- 
phaltum, have been successfully used in Berlin, for street 
pavement. After driving out the water with heat, bricks 
will take up from fifteen to thirty per centum of bitumei}, 
and the porous, brittle material becomes durable and elastic 
under pressure, the bricks are then put endwise on tC betoit 
bed, and set with hot tar. It is said that the rough usage 
which the pavement made of these bricks will stand is aston- 
ishing. A few years ago, in California^ a pavement was laid 
of bricks, those that were soft-burned being selected, which 
were saturated with boiling coal tar. They were placed end- 
wise on a bed of concrete, and the interstices filled with the 
hot tar, sand being scattered to the depth of about one-half 
(J4)inch upon the pavement, and afterward swept off. And 
now we learn from an exchange that bricks impregnated 
with creosote or bitumen have been adopted for paving pur- 
poses in Nashville, Tenn. , and with very satisfactory results. 
I'he wear is very uniform, as the softer and more porous 
bricks absorb more bitumen, v/hichhas the effect of harden- 
ing them, at the same time making them absolutely imper- 
vious, and thus protecting them from the disintegrating effect 
of frost. It is stated that pavement of this type, exposed 
for three and a half (3 j^) years to the wear of fairly heavy 
traffic, was, at the end of that period, found to be in excel- 
lent condition. The process of bitumenizing, however, 
rather more than doubles the cost of the brick. 

A POLISH FOR WOOD. 

The Vvooden parts of tools, such as the stocks of planes 
and handles of chisels, are often made to have a nice appeal - 
ance l)y French polishing ; but this adds nothing to their 
durability. A much better plan is to let ihem soak in lin- 
seed oil for a week, and rub with a new cloth for a few min- 
utes every day for a week or two. This produces a beauti- 
ful surface, and has a solidifying effect on the wood. 

TO CALCULATE THE NUMBER OF SHINGLES 
FOR A ROOF. 

To calculate number of shingles for a roof, ascertain num- 
ber of square feet, and multiply by four, if two inches to 
weather, 8 for 4^^ inches; and 7 1-5 if 5 inches are exposed. 
The length of a rafter of one- third pitch is e(iual to three- 
fifths of width of building, adding projection. 



448 

VALUABLE FIGURES. 

The following figures are wort A remembering, as they 
will save a good deal of calculation and give approximately 
accurate results with a minimum of labor : 

A cord of stone, three bushels of lime and a cubic yard 
of sand, will lay one hundred cubic feet of wall. 

Five courses of brick will lay a foot in height on a 
chimney. 

Nine bricks in a course will make a flue eight inches wide 
and tw^enty inches long, and eight bricks in a course will 
make a flue eight inches wide and sixteen inches long. 

Eight bushels of good lime, sixteen bushels of sand 
and one bushel of hair, will make enough mortar to plaster 
one hundred square yards. 

One-fifth more s:ding and flooring is needed than the 
number of square feet of surface to be covered, because of the 
lap in the siding and matching of the floor. 

One thousand laths will cover seventy yards of surface, 
and eleven pounds of lath nails will nail them on. 

One thousand shingles laid four inches to the weather, 
will cover one hundred square feet of surface, and five pound*. 
of shingle nails will fasten them on. 

FROSTED GLASS. 

Verre Givre, or hoar frost glass, is an article now made 
in Paris, so called from the pattern upon it, which resembles 
the feathery forms traced by frost on the inside of the win- 
dows in cold weather. The process of making the glass is 
simple. 

The surface is first ground, either by the sand blast or 
the ordinary method, and is then covered with a sort of 
varnish. On being dried, either in the sun or by artificial 
heat, the varnish contracts strongly, taking with it the parti- 
cles of glass to which it adheres ; and, as the contraction 
takes place along definite lines, the pattern produced by the 
removal of the particles of glass resembles very closely the 
branching crystals of frostwork. 

A single coat gives a small, delicate ettect, while a thick 
film, formed by putting on two, three or more coats, con- 
tracts so strongly as to produce a large and bold design. Hy 
using colored glass, a pattern in half-tint may be made on the 
colored ground, and, after decorating white glass, the hpak 
may be silvered or gilded. 



449 
PERFECT MITERING. 

BY OWEN B. MAGINNIS. 

The many awkward ways in which so many woodworking 
mechanics endeavor to mark and cut in soft and hard wood 
moldings, and the botching results of their efforts, has in- 
duced the writer to give the following simple and successfal 
methods which are perfect in their accuracy. 

The different conditions which exist through the careless- 
ness of those who precede him, when an operator commences 
to set in his molding, often cause him much trouble and losy 
j>f patience, as for instance, a molding being run standing on 
the little rebated lip or a raised molding being out of square, 
or an obtuse angle, instead of a little tender^ or an acute 
angle. This will of course necessitate, either the re-rebating 
of the molding by hand, or taking the arris of the corner of 
the panel sinkage as shown at A. Fig. i. Then the moldinp 




Fig. I, 

is often stuck too thin for sinkage, as will be clearly seen on 
.he left hand side of the panel at B^ and again the surface of 
the door, on account of the inequalities of the thickness of 
the pieces, especially on the back side, often varies as much 
as /^ of an inch. This difficulty is easily overcome by the 
following sure process. 

Take a small strip, and, placing the end of it down in the 
icrner, mark the arrises with a sharp pocket knife. Measure 
these depths; in the case shown here they will be, for exam- 
ple, respectively, ^-inch, j^-inch, -j\;-inch, full, ^-inch full, 
smd ^-inch, scant. Havingdone this, make4Strips, or saddles> 



45<^ 



ecjuai fu width to the different depths of the sinkage, as )^-incla 
wide, i^—^^g^ wide, and so on, each being about ^-inch thick and 
Icng isnough to go into the miter box between the saw cuts. 






Fig. 2. 
Plac3 it in the box as represented at Fig. 2, with the lip of 
the molding resting on the saddle as it will rest on the door 
frame, at the miter and saw the left-hand end (say on the ji 
scant saddle): To get the neat and exact length without 
gauging on the door. From the point where the saw crosses 
the saddle at Fig. 3, square across the bottom of the box 
with the Den -knife. These lines are the neat and exact 
lengths for either end, so if the thin edge — B, Figs, i and 3, 
of the molding, be marked at the opposite arris, holding the 
already mitered end close into its corners — -and then this 
mark be placed at the asterisk or intersection, and the 
molding sawn on the saddle necessary for the opposite cor- 
ner (say yi full saddle), and so on all around the panel, it 
will, if cut out of one piece, perfectly utersect in its profile, 
<:he lip will come to a close joint on the frame, and the thin 
sdge close to the panel. The dotted line in Fig. 3 shows 
now the molding should be neld down in the box. The best 
way is to try a pair of pattern pieces as shown at Fig. i (on 
the necessary saddle), trying the patterns in each corner. 



. C==^ 



?f 



z 



3. 



/771»u/c?V< 



A^ 



X 



2: 



Fig. 3. 
By this means it will be easy to find the exact saddle which 
will bring a good miter. Be sure they will come right 
before commencing to cut the molding all round. If it be 
too thick for the sinkage, of course it must be planed down 
on the back until it is a shaving thin, so that it will not strike 
the fillet, but press closely on the panel. 

Great care should be exercised in cutting ^he miter box, as 



43 i 

perfect mitering is almost reliant on a good box, cut exactly 
on the angle of forty-five degrees. To set the level, lay ont 
a square on a drawing-board about four inches wide. Join 
the opposite angles like at Fig. 4 (be certain it is exact to a 
hair, or the bevel will not reverse itself). Place the bevel on- 
to the lines joining the angles as it lies on the board and 
mark the miter box by it. This is the only perfect way to 
miter and. cut in raised moldings, and will always, without 
error, assure accuracy and good mitering. 

Fig. 4. 











X 






,1 ) 



Mitering flush molding or molding which does not rise 
above the surface of the frame is comparatively simple, and 
is usually done with a jack, except in the case of large mold- 
ing. All that is necessary is to first miter the left-hand end 
and mark the right hand. 

The handiest way is to commence at the right-hand 
corner next to you, and work to the farthest corner, and soon 
all round, returning to the one started from. Should the 
lengths, when placed in the panel before drawing down, be 
too long, take a rebate plane, shaving off until they be a snug, 
tight fit. 



THE VENTILATION OF BUILDINGS. 

Perhaps no single feature of modern architectural construe- 
ion is likely to secure such immediate regard in the near 
future, and'is already so conspicuously engaging the attention 
of the foremost men in the profession, as that of proper ven- 
tilation. Nor can it be denied that no feature is mor^ im- 
portant for health considerations in private homes, .ffice 



452 

buildings and public institiitions, than ttie securing of a 
steady supply of pure air and tlie coincident and correspond- 
ing removal of tlie vitiatec? air, so that the atmosphere m the 
rooms is, at all times, fresh and pure. The two points cov- 
ered in the last sentence constitute what is known as, and is 
technically termed, "ventilation." 

The expedients for obtaining a supply of fresh air to the 
room, so that there is a constant dilution and consequent 
bettering of the atmosphere, are comparativoTy simple. 
They merely imply that the air warmed by the hot-air fur- 
nace or steam coils in the cellar be taken from a place where 
it is pure (not, for instance, above a cesspool), that the ducts 
in cellar, through which the air trav^els, be air-tight (prefer- 
ably so constructed of No. 22 or No. 24 galvanized iron, 
rather than of wood), and that some automatic means be 
adopted to regulate the tem:-)erature of the air supplied to 
the rooms, without shutting off such air supply. Or, when 
steam radiators are in rooms, that they be placed helow win- 
dows, and air pass by means of proper orifices from outside 
through the radiators. 

Furthermore, in large structures, a fan driven by electric 
or steam power is often instituted for forcing in a larger 
amount of fresh air than could be secured by the natural 
suction of the warmed air. C 

But the mere supply of warmed fresh air to the rooms is 
not enough. For note, if the air in the room has no escape, 
it does not take long, whatever the fresh air supply, before 
the vitiated air contaminates and makes foul the air as it 
enters the apartment. To open the windows is the remedy 
which the uninitiated at once suggest, and, in fact, in most 
houses this is the only palliative at hand. 

It is, however, one of the first principles of ventilation, 
that the windows must not enter as an expedient. In a 
properly ventilated building the windows should never be 
open when people are in the rooms, at least in the winter 
months. For. opening the windows secures the admission of 
cold air in bulk, but does not remove the foul air, and more 
especially causes pneumonia-giving draughts, and chills the 
room, and in this way more damage is done than .by even the 
presence itself of vitiated air in the rooms. 

A warm or hot room does not necessarily signify an im- 
pure atmosphere; while we may have a room cold and the 
atmosphere still terribly impure. The unthinking never 
take this into account, and are apt to confuse the term warm 
with impure, and the term cold with pure atmosphere, as far 
as the rooms they are in are concerned. ^ 



The proper way to remove the vitiated air is by means of 
'•ent-ducts, or vertical flues leading from the rooms to the 
roof of tne building. These flues should have an aggregate 
cross-sectional area at least equal to, and preferably about 
ten per cent, greater than, the cross-sectional area of the 
fresh air inlets; and should be situated on the opposite 
(preferably diagonally opposite) side of the room. 

These vent-ducts should have openings controlled by 
registers, near the floor and near the ceilings of the rooms, 
•"ut the two registers should not be opened at the same time. 
The cross-sectional area of the registers should be twenty-five 
per cent, more than that of the vent-ducts. 

The bottom register is the one ordinarily to be used; for 
the heavy, vitiated air sinks to the floor, while the fresher, un- 
polluted air rises. When the people in the room are smoking 
profusely, it is better to close the bottom and open the top 
registers of the vent-ducts, for the smoke rises to the top, 
and is then more speedily removed. 

These vent-ducts cause a gentle draught in the same way 
that a chimney of a steam boiler or hot-air furnace does. 
The temperature in the room being higher than that of the 
external air, the temperature in the vent-ducts is also higher, 
and consequently a draught or removal of the vitiated air is 
secured, the amount depending on the area and height of the 
duct, and the difference of temperature between the ex- 
ternal air and the air in the room. ^ This system is known as 
that of natural ventilation. 

To make this removal of vitiated air still more rapid than 
IS secured by the natural draught just mentioned and ex- 
plained, one of several expedients may be adopted. An 
exhaust-fan, driven by steam or electric power, may be placed 
near the top of vent -duct, and the air exhausted from duct by 
means of this fan, thus increasing the fresh air supply through 
fresh air inlet. This is frequently adopted in public build- 
ings, where the rooms are, at times, full of people. Or the 
temperature of the air in the vent-ducts, and consequently 
the drabght and the removal of vitiated air, may be in- 
creased by any of the following means: 

1. Gas jets may be burnad in the venc-fiues near thebot- 
fom. 

2. Steam risers, through which steam of high or low 
pressure circulates, may run through the vent -ducts. 

3. Such steam risers may have a large coil near top or 
right above vent-flues proper. 

For private homes and dwellings; natural ventilation 
sufiices. For public buildings and large halls, either the fan 



454 

or tlic 5tt?am system should be preferably adopted. The ga^ 
jets give ouc a comparatively little additional heat^ but are 
inexpensive in first cost, and in running expense. 

In a paper " On the Relative Economy of Ventilation by 
Heated Chimneys and Ventilation by Fans," read by Prof. 
Wm. P. Trowbridge, of the School of Mines, Columbia Col- 
lege, before the American Society of Mechanical Engineers, 
Prof. Trov^^bridge decides that in all cases of moderate ven- 
tilation of rooms or buildings, where, as a condition of health 
or comfort, the air must be heated before it enters the rooms, 
and spontaneous ventilation is produced by the passage of 
this heated air upward through vertical flues, such ventila- 
tion, if sufficient, is faultless as far as cost is concerned. He 
consideres this a condition of things which may be realized 
in most dwelling houses, and in many halls, school-rooms and 
public buildings, inlet and outlet flues of ample cross-section 
being provided, and the heated air being properly distrib- 
uted. 

If, however, starting from this condition of things, a more 
active ventilation is demanded, the question of relative econ- 
omy of fan and heated chimney is not so simple a problem. 
Prof. Trowbridge points out that ventilation by chimneys is 
disadvantageous under one point of view in any case, viz : the 
difficulty of accelerating the ventilation at will when larger 
quantities of air are needed in emergencies; while the fan 
or blower possesses the advantage in this respect, that by in- 
creasing the number of revolutions of the fan the head or 
pressure is increased. This latter fact makes the fan prefer- 
able for the ventilation of hospitals or public buildings of 
considerable magnitude, whenever, as is customary, the activ- 
ity of the ventilation must be varied occasionally. 

Where the power required is only a small fraction of a 
horse-power, as in ventilating single large rooms or small 
buildings, Prof. Trowbridge concludes it to be evident that as 
regards cost of fuel and the care and attention required, ven- 
tilation by heated chimneys is preferable, except, of course, 
for cases where a fan is driven by machinery employed for 
other purposes than ventilation, the cost of attendance charge- 
able to ventilation being then trifling and the fan evidently 
being more appropriate. 

The construction of the building, of course, enters as an 
important factor, and often precludes the adoption of the ex- 
haust-fan system. In large structures it is always important 
to take into account, and decide upon, the system of ventila- 
tion before the plans of the building proper are finished or 
finally adopted. 



455 



BURYING A SCREW HEAD OUT uF SIGHT. 

To get the heads of nails and screws out of sight, where 
ghie can be used without any objection, just raise up a chip 
with a thin paring chisel, as shown in the drawing, and then 
set the nail in solid. This " leaf" can be covered with a coat- 
ing of glue and laid back again in place, where it must ht on 
all sides to perfection. A dead weight v/ill hold everything 
in place till the glue dries, and a few moments with the 
scraper makes the job complete. It will add to the nicety of 
the work to draw lengthwise with the grain two deep cuts 
with a thin case-knife just the width of the chisel, and this 
keeps the sides of the chips from splitting. The chisel should 
be set at a steep angle at first till the proper depth is reached, 
and then made to turn out a cut of 
even thickness until there is room to 
drive a nail. If too sharp a curve is 
given, the leaf is likely to break apart 
in being straightened out again. In 
blind nailing a narrow chip is taken 
with a tool made especially for this 
purpose, that lifts the cut just high 
enough to let in the nail on the slant, 
a set slightly concaved, being used to 
keep it from ever slipping off the 
head, and the upraised cut driven 
down again with the hammer. 

HIP AND VALLEY ROOF FRAMING. 

A simple way of laying out a hip or valley roof and 
finding the length of jack rafters, cuts and bevels, is shown 
in the accompanying sketch. The method followed is com- 
paratively simple and easily understood. 

Lay down the plan of the building A, B, C, 7J, fmd the 
center line of the ridge ^ F, and show the plan of hips A F 
and B F, also the jacks G If and IK. 

To find the length of the common or straight side rafters, 
lay off on the ridge line F F the height of the pitch E M. 
From the point A^, which is the outside edge of the wall 
plate, join N M. This will give N M as the extreme 
length, on the upper edge, of the common rafter which is to 
stand over the seat F N. 

In order to find the length of the hip rafi^iS vvhichi will 
stand over the seats C E or B I\ draw the line O E 
square with the line E C, and make O E=AI E the height 
ot the pitch. Joiri the point C with the point O, thus 




45^ 

obtained, which will give the length to the hip rafter on its 
upper edge. 

The length of the jack rafters U generally obtained by 
direct measurement, but the following method will be found 
correct. Produce the line JV £^, and make tV /^ equal to 
the length of the common rafter, so that ^V /'=/!/ A', join 
P C, which will equal C O; produce the seat of the jack 





rafters k i and g h, until they intersect P C m I and m^ 
and then i I and g in will be the correct lengths for the 
jack rafters. 

In raising a roof of this description, it is usual to cut the 
ridge E F and the common rafters which abut against it at 
each end ac ? t R F, In placing them in position they are 
fastened plumb over their seats by braces, and the side 
rafters are placed each against its mate, as i against /, 2 
against 2, j against j, and so on. 

When all the side rafters are in position, the hips are 
inserted, and their accompanying jacks. 

PAINTING AND VARNISHING FLOORS. 

A French writer observes that painting floors with any 
color containing white lead is injurious, as it renders the 
wood soft and less capable of wear. Other paints without 
white lead, such as cchre, raw umber or sienna, are not in- 
jurious and can be used with advantage. Varnish made of 
drying lead salts is also said to be destructive, and it is 
reccommended that the borate of manganese should be used 
io dispose the varnish to dry. A recipe for a good floor var* 



^5/ ' 

nish is given as follows: Take two pounds of pure white 
borate of manganese, finely powdered, and add it little by 
little to a saucepan containing ten pounds of linseed oil, which 
is to be well stirred and raised to a temperature of 360"^ Fahr. 
Heat 100 pounds of linseed oil in a boiler till ebullition takes 
place; then add to it the first liquid, increase the heat and 
allow it to boil for twenty minutes. Then remove from the 
fire and filter the solution through cotton cloth. The var- 
nish is then ready for use, two coats of which may be used.^ 
with a final coat of shellac, if a brilliant polish is required. 

A COLOSSAL STICK OF TIMBER. 

A colosal stick of lumber from Puget Sound has been con* 
iributed to the Mechanics Exhibition at San Francisco. Its 
length is 151 feet, and it is twenty by twenty inches through. 
It is believed to be the longest i^iece of timber ever turned out 
of any saw mill. 

A i^\^ years ago mechanics cared 'very little about winter 
work of any kind. They rather looked forward with pleas- 
ure to the prospects of a long rest. Things have been chang- 
ing recently, and the tendency now is to secure all the winter 
work possible: One reason is, there are more building and 
loan associations, more insurance societies, more lodges and 
more organizations of one kind and another, all of which 
must be kept up. Besides, there is an increasing amount of 
work that has heretofore been done in summer. The cost of 
labor in a good many vocations is less in winter than it is in 
summer, owing to the small amount to be done and the greater 
number seeking it. 

PLASTER FOR MOLDINGS. 

Where walls and ceilings are to be molded whilst yet in a 
plastic state, some decorators are using a fibrous plaster, with 
the object of securing greater firmness and tenacity. The 
idea itself is not new, animal hair having formerly been inter- 
mixed with lime, but this is a new application. In England 
and France a fine wire netting is at times inserted between 
two courses of plaster, to afford greater firmness in holding 
picture frames. The tenacity of some of the old moldings 
in old New York houses, whilom aristocratic, is very 
remarkable, retaining as they do their original sharpness oi 
outline. 



458 
THE SWEATING OF CHIMNEYS. 

Tlie sweating of chimneys is now believed to be due to 
condensation of the moisture in the air that is conflned in a 
poorly ventilated chimney fiue. The trouble, as our corre- 
spondent indicates, is chiefly to be found occurring in small 
chimneys, and in such chimneys whose flues start from the 
second or third story of a building. The sweating is the 
most copious when a fire is started in a place that has been 
for some time in disuse, or, in other words, when the flue is 
cold. The humidity of the air is a large factor in the 
phenomena of sweating. If the air be charged with moisture, 
the flue cold, and a fire newly kindled, the conditions are 
favorable for sweating. It is only under these favorable 
conditions that a well-ventilated chimney will begin to sweat, 
but the sweating will not continue. If sweating should 
continue in a chimney after a fire is fairly under way, it can 
be safely concluded that the chimney needs an opening near 
the ground to provide a better circulation of air within the 
flue. It may be, as our correspondent suggests, that rain 
may beat in and cause the same effect as sweating, especially 
where the rain has continued for several days together, and 
in that case a cowl, such as has been lately described in 
Building, in House and Stable Fittings," would cure the 
disease by excluding the rain; but such occurrences are 
exceedingly rare, and we have seen chimneys guilty of sweat- 
ing that were provided wi^^h the most approved form of cowl, 
and the remedy applied has been to insert an air-brick at the 
r>ase of the chimney to secure better ventilation, so as to 
lessen condensation, and the device has proved successful. 
Cowls prove useful only so far as they promote ventilation 
by increasing the circulation within the chimney flue. A 
cowl may be so improperly applied to a flue as to promote. 
Instead of abolishing, sweating. The main point is to pro- 
vide an ingress of air sufficient to tax the extractive capacity 
of the cowl that is used. 

STRENGTH OF HORSES. 

It is stated that, if one horse can draw a certain load over 
a level road on iron rails, it will take one and two-thirds horses 
to draw the same load on asphalt, three and one-third horses 
to draw it on the best Belgian block, five on the ordinary 
Belgian pavement, seven on good cobblestones, thirteen od 
bad cobblestones, twenty on an ordinary earth road, and toty 
on a sandy road. 



459 
SMOKY CHIMNEYS AND HOW TO CURE THEM. 

A smoky chimney is a complaint we are often called upon 
to deal with, and the best way of building chimneys which 
should not smoke into the rooms, and of remedying existing 
chimneys which are liable to do so, is a matter of great im- 
portance to estate clerks of works. There are many small 
matters in building new chimneys which, together, may be a 
means of preventing them from smoking at the wrong end ; 
but my intention at present is to deal crJy with the shaft or 
stack, or portion outside the roof, and my object is not to 
give ornamental elevations of chimney heads, which are un- 
necessary for the purpose of this article, but to explain a way 
of forming them which 1 have many timesfound to give relief 
to inveterate smokers. A common shaft, such a one as 
would be adapted for existing old cottages, is 2^ bricks or 
I fto ioj4 in. in width, and in my opinion none should be less 
than this, with a 9-inch earthenware flue-pipe built in solid; 
this I usually commence on the damp course, which should 
be just above the flashings of roof. As the area of the round 
pipe is smaller than the 14-inch by o-inch brick flue 
on which it is placed, a quicker current of air or draught is 
thereby generated, and in windy weather a check is given to 
sudden down-draughts. Another advantage in a flue-lined 
stack is that there is no danger of the brickwork cracking 
when the soot in the flue is on fire, and which, owing to the 
scarcity of chimney-sweeps, is often the case in country places. 
Stoneware drain pipes, however, are quite unfit, as they are 
liable to split with the heat ; but the tubes made of fire-clay 
or terra-cotta, only should be used. Another help is to keep 
the stack dry ; a damp flue is generally a smoky one, and if a 
fire is lighted in the fire-place, say, of a disused bed-room, it 
is a common occurrence to see the smoke puff down violently 
and the chimney is said to have a down-draught, and by many 
people is assumed to be badly constructed, whereas, perhaps, 
it may be built in the best possible manner except that it will 
not keep out rain and damp. The rain may come through the 
sides of the stack, or it may come downward through the head ; 
at any rate the chimney for some distance from the top is, in 
wet weather, cold and soppy. I roof the chimney top with 
plain tiles, with the object of protecting the head and 
permitting the rain to drop off at the eaves instead 
of running down the stack and making the flue cold^ 
and the stack outwardly black and soot stained I 
bed the tiles in cement, using copper nails driven into the 
laUer through the pin holes— or a plain, cemented weather- 



460 

iiig looks fairly well. But by forming the covering with tiles 
a good drip is obtained, which is not so readily dene with 
cement. Another point is not to make the slope or 
pitch of a suitable angle, and this, in my opinion, 
should be about 45 degrees, as I find that inclination most 
effectual; when the wind strikes the slope it takes an upward 
direction, and, as a matter of course, carries the smoke with 
it. 

Some time since a gentleman living by the seaside was 
much troubled with smoky chimneys, and asked me what 
was the best thing to do ; I told him near about what I have 
just now written, and a short time afterward I received a letter 
(which I must confess somewhat scared me) saying he had 
decided to pull down his chimneys and rebuild them on my 
principle, and desired me to order for him two truck loads of 
George Jennings' flue pipes at once. This I did, and waited 
anxiously for the result; at last I was gratified by hearing 
" Chimneys are a great success," but it was summer time,'and 
I was not so sure how they would act in cold, boisterous 
weather by the seaside, where every patented smoke-curer 
had apparently been tried by some one or other ; but eventu- 
ally I was glad to learn that they continued to draw well. 

I have proved this system of chimney stack building to be 
good in a large number of cases ; for instance, my ofiice 
chimney is directly under the branches of a large tree, and 
the fire is on the hearth, yet I am never troubled v/ith smoke. 

For economizing heat in single houses or detached cot- 
tages, we all know it is the best plan to get the chimney on 
the inside, and not forming a portion of the outer walls, as in 
the latter case they are much more likely to smoke, and we 
also know that register grates, or grates with doors a few- 
inches above the fire, generally make the fire draw ; they not 
only draw the smoke, but a greater portion of the heat as 
well, and necessitate getting very close to the fire to obtain a 
portion of the heat going up the chimney. To my mind, 
there is nothing to equal a fire on the hearth, and wood, if 
Vou.can get it, in preference to coals. 

There is much might be said about set-offs in flues, and I 
know they are objected to as a rule, but I believe a chimney 
"with . one or two set-offs is all the better for it. I also 
believe chimney heads built in cement mortar true economy; 
the latter makes good Avork and looks well, long after chim- 
ney heads buiit with lime mortar, which soon show startling 
mortar joints and crumbly bricks. How often do we find 
old chimney heads want repointing, for the weathe** loosens 
the mortar and the birds carry it away. 



461 

The summary of my experience is briefly this: 

1. Put a dam^) course to new chimneys, or insert one in 
old chimneys. 

2. Line the chimneys with fine pipes above the damp 
course. 

3. Roof the chimney tops'carefuUy. 

4. Don't forget a good projecting eaves-drip to the chim- 
ney-head. 

■i. Build the heads with cement mortar. 

FACTS ABOUT FUENACES. 

In February, 1881, the committee of hygiene of the Medi- 
cal Society of Kings County rendered a report, which is 
published in full in the proceedings of that society, upon 
catarrh, and whether .that disease was aggravated by resi- 
dence in cities. The opinions of a large number of phy- 
sicians of long experience were obtained, and their testimony 
showed "that, though climatic and city influences have much 
to do with the creation of catarrh, yet defective heating, 
lighting, airing, sunning and drainage of houses, with im- 
proper views as to air, clothing, bathing and exercise, are 
the main causes," Individual physicians laid special stress 
upon individual influences, as "dry and irritating air from 
villainous furnaces, increased furnace heat and artificial 
methods of living." 

Furnace air jper se is not so unwholesome, but it is the 
absence of ventilation which makes it so. If a furnace is of 
sufficient size to warm a building without opening every 
draft and heating the fire-pot red-hot, and if the fresh air 
supply is taken from a proper source and not from a damp 
area or uncleajU cellar; and, furthermore, if there are sufft 
cient openings at the top of the house to allow the impure 
air which rises to that point to escape and thus cause a con- 
stant circulation of sufficiently warmed but not overheated 
air through the house, under these conditions a furnace is 
not objectionable. 

Furnaces are often badly located. It is easier to force 
warm air through a furnace flue fifty feet away from the 
prevalent wind than ten feet in the opposite direction. 
Hence the furnace should be placed nearest the northern 
side of the building, or two should be provided. Hot-air 
flues should not be carried for any distance through cold cel- 
lars, halls or basements, as they will become chilled, and 
will not draw without being cased with some non-conducting 
material, as mineral wool. 



4^2 

Don't set a furnace in a pit, especially in a wet soil where 
water will collect after every rain storm, but stand it on 
brick arches, so as to raise it above the ground ; also cement 
the pit. It is unfortunately very common to find such 
depressions filled with water ; this causes rusting of the fur- 
nace itself and damp in the cellar. In very many houses 
occupied by persons of means, the furnaces are no longer 
used, but have been replaced by open fires. This is costly 
comfort, but it is a commendable plan, as it furnishes ample 
ventilation to the living rooms. It is desirable that one room 
should at least be thus supplied with a careful and sanitary fire. 

Where fresh-air inlets are carried from the house drain to 
the front of a house at the yard level, they should not be 
located near to the cold-air supply, as there is a chance that 
during heavy states of the atmosphere a down-draft may be 
created, and the foul air sucked into the air box and thence 
upward into the house. Registers should never be placed at 
ihe floor level, as they will collect dust and sweepings, which 
are Hable to take fire. 

Farnaces with heavy castings heat slowly and are less easily 
cracked or warped, and they cool more slowly, so that the 
heat evolved is more uniform. It is well to retain the air 
close to the fire -pot, and thus keep it longer in contact with 
the fire-heating surface. 

Water pans are often badly arranged so that they admit 
dust, and as they are seldom cleaned that may become offen- 
sive. They should always be supplied by a ball-cock so as to 
be autom.atic, rather than by a stop-cock which has to be 
opened by a servant, who may be neglectful. 

Attempts have been made to filter the air before entering 
the furnace, but they usually lail. A screen of galvanized iron 
wire of 1-16 mesh will exclude most floating material from 
the air. The air supply is sometimes taken from the attic, 
but it is apt to be dusty and impure. Others take it from 
vestibules of halls or piazzas, which are not bad places. 

STEAM vs. HOT-WATER HEATING. 

Hot water as a heating agent is one of the oldest in use, 
nnd has a number of advantages in its favor. For mild 
climates it answers very well. For northern latitudes, how- 
ever, and in countries such as Canada and most of our north- 
ern States, having long, severe winters, hot-water heating ii 
not in general use on account of the following objections: 



4t>3 

High First Cost — Hot water, as generally used, only 
gives off two-thirds the amount of hc^at per square foot of 
radiating surface which steam will give under similar cir- 
cumstances. To get the same results as from steam it 
therefore requires about fifty per cent, more of radiators, 
and a corresponding increase of piping. 

Added to the expense of this extra material is that of 
labor, which increases in the same proportion, thus 
making the entire first cost of hot water about one- 
third higher than steam. 

Leakage — As all the pipes are continually full of water, 
any leakage will rapidly flood the house, causing trouble 
and damage. With steam , the flow-pipes contain no water 
whatever, and the return drip-pipes but very little, so 
that in event of a leakage the wate would be discovered 
and stopped long before it could do any damage. 

No Way to Shut Off—V^e have never yet seen, a hot 
water radiator which can be turned off and yet allow the 
water within it to flow back to the boiler; the construc- 
tion of the radiator being such that all the water must 
circulate up and down between divisions connected 
alternately at the toj) and bottom. 

When the radiator is turned off, these divisions still re- 
main full of water which has no chance to run off. It is 
therefore necessary to keep all the radiators in the house 
running all the time, or else take the chances of their 
freezing and giving trouble if they are shut ofl. Now 
there are certain rooms in almost every house, such as 
guest-rooms, which are only occupied occasionally, and 
it would be a useless expense and inconvenience to keep 
them constantly warmed. The advantage of steam over 
hot water in this respect is evident. With steam you can 
shut off any radiator you please, and keep every room in 
your house at the exact temperature disired, without in- 
convenience or waste of heat. k 

Freezing and Bursting — It is a curious fact that hot 
water will cool down and freeze much quicker than ordin- 
ary water under the same circumstances. The first effect 
in boiling water is to drive off all its air, hence, becoming 
more solid and condensed, it is very susceptible to cold 
and will freeze very easily. If the fire in the boiler from 
any reason goes out, the water of course soon stops circu- 
lating, and in cold weather the pipes will rapidly freeze 
and burst ^ 



464 

Difficulty of Eegulation-^-ln zero weather it is difficult lo 
keep warm by hot water, unless thfehi'S is a great amount of 
heating surface, and t>ien in mild weather you ar^ liable at 
any time to have too much heat. This is especially notice- 
able in any sudden change of temperature. 

Hot water, being slow in acquiring heat and slow in part- 
ing with it, is consequently difficult to regulate with any 
degree of satisfaction. 

This feature is seen in greenhouse heating particularly. 
When the sun is shining, on account of the great amount of 
natural heating glass surface, the temperature soon runs up 
above the normal, causing a necessity for opening the ven- 
tilators and so wasting the heat. And should the tempera- 
ture once get down, it takes a long time to get it up again. 

The advantage of steam in this case is apparent, as it is 
capable of being handled and regulated rapidly, and there- 
fore is superior to any other method wherever an even and 
uniform temperature is desired either for a greenhouse or a 
dwelling. 

Comparative Economy.— Ca,Yefu\ experiments have recently 
been made by parties owning many greenhouses— some of 
which are warmed by steam and others by the most approved 
of hot- water heaters— for the purpose of accurately deter- 
mining the relative cost of fuel in each case. They had 
nothing to gain by such experiments except the truth, as, 
with all florists, coal is a very heavy item and one of the 
principal expenses attending the running of a greenhouse. 

Without entering into details, it has been demonstrated 
that greenhouses may be heated by steam on two-thirds the 
quantity of coal required, for a hot-water apparatus. This 
fact has become so well ^established, that to-day steam is 
very rapidly taking the place of every other method for 
warming greenhouses. 

The objections to hot water for this class of buildings is, 
moreover, much less than for residences, on nearly all the 
preceding five points. For instance, a leakage of a pipe can 
do no harm, as in a house, and there is, of course, no occa- 
sion to shut off any portion of the system, as is sometimes 
desired in a house. 

Although the expense of a change from hot water to steam 
is heavy, yet the advantages secured are so great and ai)- 
parent that it will not be long before hot water as a heating 
agent will be practically abandoned in every kind of building. 



405 

INTERESTING FACTS ABOUT ISINGLASS. 

Isinglass consists of the dried swimming bladder of fishes. 
The bladders vary in shape, according to their origin, and 
tiicy are prepared for the market in various ways. Some 
are simply dried while slightly distended, forming pipe 
isinglass. When there are natural openings in these tubes 
they are called pi^i-sers. When the swimming bladders are 
slit open, flattened, and dried, they are known as leaf isin- 
glass. Other things being equal, the value of a sample is 
determined by the amount of impurities present. These im- 
purities are ordinary airt, mucus naturally present inside thff 
bladder technically called grease, and blood stains. If tiie 
bladders^ were hung up to dry with the orifice downward, the 

mucus could be drained off; but usually the fishermen fear 
the reduction in weight, and take care to retain all they can. 
It is necessary to insist on having the bladders slit up and 
rinsed, clean as soon as they are removed from the fish. This 
would so much increase the value of the product that the 
extra labor would be very profitable. Blood stains cannot 
be removed without injuring the quality. If any process 
could be devised effectual for this purpose, a valuable dis- 
covery would be made. 

The uses of isinglass are not very varied. The largest", 
quantity is used by brewers and wine merchants for clarifying. 
This property is extraordinary, for gelatin, which seems chem- 
ically the same thing as isinglass, does not possess it. 

For clarifying purposes the isinglass is " cut " or dissolved 
in acid, sulphurous acid being used by brewers, as it tends to 
preserve the beer. When reduced to the right consistence, a 
little is placed in each cask before sending it out for consump- 
tion. 

There seems to be only six isinglass cutters in England, 
all. being in London. The sorted isinglass is very hard and 
diflicult to manipulate. It is soaked till it becomes a little 

E liable, and is then trimmed. Sometimes it is just pressed l)y 
and on a board with a rounded surface ; at others it is run once 
between strong rollers to flatten it a little. The next process 
is that of rolling. Very hard steel rollers, powerful and 
accurately adjusted, are used. They are capable of exerting 
a pressure of lootons. Twoareemployed, the first to bring tlie 
ismglass to a uniform thickness, and the smaller ones, kept cool 
*?ya current of water running through them to reduce it to 



460 

little more than the thickness of writing paper. From the finer 
rollers it comes in a beautifully transparent ribbon, many 
yards to the pound, " shot " like watered silk in parallel lines 
about an inch broad. It is now hung up to dry in a separate 
room, the drying being an operation of considerable nicety. 
When sufficiently dried, it is stored till wanted for cutting, or 
it is sold as ribbon isinglass to all who prefer this form. 

MODERN USES OF TIN. 

The uses of tin have greatly increased during the last few 
centuries of our era. Salmon, in his splendid work on casting 
tin (1788), describes the methods of work, and mentions the 
objeccs manufactured from this metal. We see from the 
plates of his atlas that table services (spoons and forks) 
pitchers, jugs, candelabra, lamps, surgical instruments, chem- 
ical apparatus, boilers for dyeing scarlet, etc., were being put 
upon the market in the most varied forms of that epoch. 

Griffith, between i840and 1850, perfected the manufacture 
of tin utensils in a single piece. This industry became espe- 
cially developed in France from 1850 to i860. 

In i860 America began manufacturing impermeable boxes, 
without soldering, from single pieces of metal. 

To-day tin is being used in the manufacture of bronzes for 
guns, money and medals, and in the alloys used for making 
measures of capacity for liquids. Its unalterability in the air, 
and the harmlessness of its salts when they exist in small 
quantity, cause it to be employed in our day in the manufac- 
ture of culinary vessels and utensils. Advantage is taken of 
its malleability to form from it those thin sheets that are 
used as wrappers for chocolate, tea, etc. 

In the various bronzes that it forms with copper, we have 
evidence of the influence that relative proportions of the two 
metals have upon the properties of the ailoy. Thus gun bronze, 
which contains ten parts of tin to ninety of copper, is remark- 
able for tenacity. The bronze of tom-toms and bells, which 
differs from the last named only in its larger proportion of 
tin (twenty to eighty of copper) is, on the contrary, very brit- 
tle, although it fortunately possesses greater sonorousness 
than gun metal does. On still further increasing the propor- 
tion of tin to thirty-three parts per sixty-seven of copper, we 
obtain a white alloy capable of taking a polish that causes it 
to be used for the manufacture of telescope mirrors. Upon 
uniting with tin, copper loses its ductility. The alloys of 
these two metals increase in density through being hardenedf 
as they do also by being hammered. 



407 

A mixture of twenty parts of tin with eighty of copper 
g^ives an alloy which is brittle at a bright red heat and when 
cold, but wnich is malleable at a dark red heat. 

When alloyed with lead, the tin forms plumbers' solder. 
Associated with mercury, it gives the silvering of looking- 
glasses. Besides this, it enters into a host of fusible alloys or 
compositions, known under the general name of white metal. 
One of these alloys, composed of tin, antimony and copper, 
is very much used as a bushing for engine bearings. For thie 
purpose the following are very good proportions : Tin, 1005 
antimony, 10 ; copper, 10. It is also alloyed with antimony 
alone, or with bismuth. It serves for tinning copper and iroiv 
kitchen utensils. To this effect the wrought -iron utensils 
are cleaned with sand and then wiped, and afterward im- 
mersed in a bath of molten tin, and finally rubbed with tow 
saturated with sal-ammoniac. Food cooked in tin vessels has 
a slight fishy taste, because it dissolves a little of the tin, just 
as food prepared in iron contracts a slight taste of ink: 

Tin is used in enormous quantities also in the manufacture 
of tinplate, In order to prepare this, the sheet iron designed 
for the manufacture of it is cleansed by plunging into diluted 
sulphuric acid, which dissolves the pellicles of oxide. Then 
it is rubbed with sand and immersed in melted tallow, and 
afterward in a bath of tin covered with tallow. When taken 
out it is tinned, there having formed upon the surface of the 
theet iron a true alloy of iron and tin covered with pure tin. 
Tin plate is as unalterable as tin itself, because the iron does 
not come into contact with the air at any point; but if, upon 
cutting it, we expose the iron, oxidation proceeds more rapidly 
than it would if the iron had not been tinned. 

Upon washing the surface of the tinplate with a mixture 
of hydrochloric and nitric acids, we remove the superficial 
layer, and render visible the crystallized surface of the tin and 
iron alloy. We thus obtain what is called moire metallic or 
crystallized tinplate. 

It now remains for us to say a few words about the new 
and important use of tin for the preparation of phosphor 
bronze. 

In the melting of bronze the absorption of oxygen is 
very detrimental, the formation of an oxide of tin rendering 
the metal brittle. In former times an endeavor was made to 
prevent this oxidation by stir/ing the mass with wood, or by 
adding a little zinc to it ; but for the last fifteen years 
greater success has been obtained by the addition of a little 
phosphorus This substance extraordinarily increases the 
compactness, toughness and elasticity of the product, and 



468 

gives it, in addition, a beautiful golden color. GuiiS, 
statues, ornaments and bearings are now cast from phosphor 
bronze with the greatest success. 

Kunzel, of Dresden, has taken out a patent for an alloy 
composed one-half to three parts, by weight, of phosphorus, 
from four to fifteen of lead, from four to fifteen of tin, and 
for the rest, copper up to lOO. 

Schiller & Sewald, of Graupen, prepare two kinds of 
phosphor broaze ; one with 2^ and the other 5 per cent, of 
phospnorus. The demand for this article is daily becoming 
more extensive. 

The most ihiportant uses of tin are, in Asia, for tinning 
copper, and in Europe and America, for the manufacture of 
objects from tinplate. The manufacture of bronze and 
white metal likewise consumes a large quantity. 

USES OF MICA. 

The peculiar physical characteristics of mica, its resistance 
to heat, transparency, capacity of flexure and high electric 
resistance, adapt it to applications for which there does not 
appear te be any perfect substitute. Its use in windows, 
in the peep-holes on the furnaces used in metallurgical pro- 
cesses, as well as the ordinary use in stoves for domestic pur- 
poses, are examples of its adaptability to specific purposes 
which it does not seem to share with any other material. Its 
fitness for use in physical apparatus is represented by its 
application for the vanes on the Coulomb meter, recently in- 
vented by Prof. George Forbes, F. R. S. For electrical 
purposes mica has proved useful, acting as an insulator be- 
tween the segments of commutators of dynamos and safety 
fuses in lighting circuits, also as the base part of switches 
handling heavy currents, to obviate the dangers of ignition 
by the arc formed when the switch is changed. For this 
latter jmrpose it shares the field with sheets of slate. Both 
of these uses were first suggested a number of years ago by an 
insurance expert in America in the course of regulations gov- 
erning the safe installation of electricdight plants. As a 
lubricator, mica answers a veiy peculiar purpose for classes 
of heavy bearing, where the powdered mica serves a useful 
office in keeping the surface separate, thereby permitting the 
free ingress of oil. "^It is used in roof-covering mixtures in a 
powdered condition in combination with coal tar, ground 
steatite and other materials, its foliated structure tending to 
bond the material together. Not affected by ordinary chem- 
icals which are corrosive to many other substances, it has 



J69 

been applied in the valves to sensitive automaiic sprinklers, 
where a sheet of mica placed over a leather disk has proved 
to be non-corrosive, and without possibility of adhering to 
the seat, while the leather packing rendered the whole suffi- 
ciently elastic to provide a tight joint. 

IMPROVED PROCESS OF TINNING. 

An improved process of coating metals with tin, by Borthel 
and Holler, of Hamburg, is said (by a metropolitan contem- 
porary) to possess the advantage of preventing, or at least 
delaying, oxidation. The process can be employed with 
special advantage for tinning cast-iron cooking utensils, 
household and other implements of cast iron, as the employ- 
ment of poisonous enamel is avoided and a much higher 
degree of polish attained. The process can also be employed 
for protecting architectural or other iron decorations from 
rusting by the coating of tin or other metal, without detri- 
ment to the sharpness of the form, as is the case with the 
customary oil or bronze paints. In order to produce a per- 
fectly even coating of tin on cast iron, the same is first provided 
with a thin coating of chemically pure iron, regardless of the 
form of casting. This coating is produced in galvanic man- 
ner in a bath composed as follows : Six hundred grammes 
of sulphate of iron, FeS04, are dissolved in five liters of water, 
to which add a solution of about 2,400 grammes of carbonate 
of soda, Na2C03, in five liters of water. The precipitate of 
ferro-carbonate (FeCo3) resulting is dissolved in small quan- 
tities in so much concentrated sulphuric acid until the fluid 
has a green color. The bath is then rendered aqueous by 
adding about twenty liters of water. Blue litmus paper 
dipped in the bath must assume a deep claret color, and red 
litmus paper remains unchanged. 

The objects to be provided with a coating ot chemically 
pure iron are placed in the bath opposite to the abode of cast 
or wrought iron or iron ore, and both parts connected to the 
corresponding poles of a dynamo machine, electric battery, or 
other appropriate source of electricity. In a very short time 
the,obiects placed in the bath are covererl with a coating of 
iron, the thickness of which depended on the duration of the 
action of the bath or the strength of electric <r^u-rent. The 
coated objects are then well rinsed inclci'.]? wat ;r, 4i"ied, then 
painted with, or immersed in, a soluiion r-<( qimmonia in 
chl6ride of zinc alone, and then immersed i^/ a vessel contain- 
ing tnolten tin The tin adheres witl. -^jfc^at tenacity to the 
prepared surface, and the surplus of tiv' ^^^ai be readily removed 



470 

by a brush, or any other manner. If the object to be tinned 
is of such size, or so compHcated in form, that it cannot be 
readily immersed in moUen tin, it can be placed in a galvanic 
tin bath, which can be readily made in any desired size, and 
be provided w^ith a layer of tin of desired thickness, "^hich, 
after having been painted either with a solution of chloride of 
zinc or ammonia in chloride of zinc, can be heated to such a 
degree that the tin is equally melted on the object. 

In like manner objects cast or made of lead or other 
read]ly melting metal, which would lose their form by melt- 
ing when immersed in molten tin, are, previous to tinning, 
provided with a coating of pure iron, and are then provided 
with a coating of tin in a galvanic bath, as mentioned above, 
without being subjected to heat for melting the layer of tin 
deposited on the same. With objects of wrought or rolled 
iron, or which do not require the before described treatment 
— id est, the production of a coating of chemically pure 
iron — it will be sufficient to carefully clean the same and 
paint them with a solution of ammonia or chloride of zinc 
or a concentrated solution of chloride of zinc. This tinning 
process combines the advantage of simple manipulation and 
the great durability of the coating with cheapness of manu- 
facture, which is partially attained in the saving of tin. 

SOLDERING. 

The term soldering is generally applied when fusible 

alloys of lead and tin are employed for uniting metals. 

When hard metals which melt only above a red heat, such 
as copper, brass or silver, are used, the term brazing is some- 
times used. Hard-soldering is the art of soldering or uniting 
two metals or two pieces of the same metal together by 
means of a solder that is almost as hard and infusible as the 
metals to be united. In some cases the metals to be united 
ase heated, and their surface united without solder by flux- 
ing the surfaces of the metals. This process is then termed 
burning together. Some of the hard-soldering processes are 
often termed brazing. Both brazing and hard-soldering is 
usually done in the open fire on the brazier's hearth. A 
soldered joint is more perfect and more tenacious as the 
point of the fusion of the solder rises. Thus, tin, which 
greatly increases the fusibility of its alloys, should not be 
used for solders, except when a very easy -running solder is 
wanted. Solders made with tin are not so malleable and 
tenacious as those prepared without it. The Egyptians sol- 
dered with lead as long ago as B. C. 1490, the time of Moses. 



47* 

Pliny refers to the art, anc . says it requires the addition oi 
tin to use as a solder. The tin came mainly from the Cas- 
siterides (Cornwall). Plumbers use solder composed of two 
parts of lead and one of tin, and a very slight variation in 
the quantities makes a very considerable difference in the 
working and also m the soundness of the joint. If a slight 
excess over the above proportion of lead is used, the solder 
is more difficult to work, and the joint when made fre- 
quently leaks, the water passing through the small cellules or 
pores in the metal, and the joint is then said to " sweat." If 
an excess of tin is used, the solder melts too easily, and con^ 
siderable difficulty is found in keeping it on the joint, audit 
cools so suddenly that the joints always look rough and 
ragged at the ends. They sometimes require trimming up to 
make them look better ; this solder also keeps running, and 
then congealing, in such a way as to be difficult to keep 
it at a workable heat Small portions of the metal also 
keep sticking to the cloth used for molding (technically 
called wiping) the joint or seam as the case may be. 

Plumbers' solder, with the above proportions, on being 
melted, and then allowed to cool, will generally exhibit sev- 
eral bright spots on its surface, due to the two metals partly 
separating. These bright spots are generally a very sure 
guide as to the proper quantities of each metal used. If 
none are seen, it is too coarse; and if too many are seen, it 
contains too much tin and is said to be too fine. If the spots 
are small the metal may not be good, although it may have 
beyond its proper quantity of tin; but if the spots are abcut 
the size of a threepenny piece the solder very rarely fails to 
work well. In uniting tin, copper, brass, etc., with any of 
the soft solders a copper soldering-bit is generally used. This 
tool and the manner of using it are well known. In 
many cases the work may be done more neatly without the 
soldering-bit by filing or turning the joints so that they fit 
closely, moistening them with the soldering fluid described 
hereafter, placing a piece of smooth tin foil between them, 
tying them together with binding wire, and heating the 
whole in a lamp or fire till the tin foil melts. Pieces of brass 
are often joined in this way so that the joints are invisible 
With good soft solder almost any work may be done over a 
spirit lamp, or even a candle, without the use of a soldering- 
bit. Advantage may be taken of the varying degrees of 
fusibility of solders to make several joints in the same piece 
of work. Thus, if the first joint has been made with the 
fine tinners' solder, there would be no danger ^of melting it 
in making a ioint near it with bismuth solder. The fusibil* 



472 

ity of soft solder is increased by adding Dismuth to the com- 
position. An alloy of lead 4 parts, tin 4 parts, and bismuth 
I part, is easily melted; but this alloy may itself be soldered 
with an alloy of lead 2 parts, bismuth 2 parts, and tin i part 
By adding mercury a still more fusible solder can be made. 
Equal parts of lead,bismuth and mercury, with two parts of 
tin, will make a composition which melts at 122 degrees 
Fahr. ; or an alloy of tin 5 partSj lead 3 parts, and bismuth 
3 parts, will melt in boiling water. In melting these solders 
melt the least fusible metal first in an iron ladle, then add the 
others in accordance with their infusibility. It is convenient 
— and in fact, often necessary — to have solders which will 
melt at different degrees of iem.perature, to avoid the risk of 
spoiling the work by subjecting it to too great a heat, when, 
with a little easy -flowing solder, there would be no danger. 

POINTS ON SOIDERING. 

For tinning soldering coppers nothing is bette"^ <han a 
soft -burned brick to contain the tin and solder. Dig a cavity 
on the side two or three inches long, and wide enough to 
receive the soldering tool. Melt some solder in the cavity thus 
formed, and throw in some pieces of sal-ammoniac and rosin. 
See that the copper bits are hot enough to melt solder ; a 
great heat will not tin as well as a low one. Rub the tool 
on the brick, melting the solder, ammoniac and rosin. The 
brick scours the copper bright, and the flux causes the solder 
to adhere very easily. One of the worst things ever 
attempted is to solder a dirty job with a dirty, untinned 
copper. 

See that the surfaces to be soldered are clean. If not, 
make them so by filing or scraping ; then protect the surfaces 
from oxidation by an application of flux or muriatic acid in 
which zinc has been dissolved. Have the soldering copper 
hot. Hold it two inches from your face, and the right 
degree of heat will soon be learned. When all of these 
conditions exist, the melted solder will flow along the seam. 
with the greatest ease, leaving a smooth, well-finished surface 
behind it. 

To dc work in the best manner and the easiest, a flux 
should be provided for each metal to be soldeied. The 
hydrochloric (muriatic) acid and zinc flux is worthless when 
rust is to be avoided, for in some cases the acid continues 
to act after the soldering is done, and in a few months niay 
eat far enough lo separate the solder from the work. In 
this case, of course, the joint falls apart. 



473 

In soldering zinc some use muriatic acid diluted with 
water for a flux, and the rusting action is to be feared in 
this instance, but may be lessened by adding soda carbonate 
(washing soda) to the acid. There are few pieces that can- 
not be soldered without the use of an acid flux, and rosin 
will do nearly as well if a little oil be added, or if the solder- 
ing copper be dipped in acid and then into oil before apply- 
ing it to the seam with rosin on it. 

Sal-ammoniac is the proper flux for copper, and this 
agent works well with tin, but it is not necessary, for rosin 
is all that is needed. Lead is perfectly fluxed by tallow (the 
plumbers call it " touch " j, but may be soldered with either 
of the other fluxes. 

NEW METHOD OF BRONZING IRON. 

The following method is successful in producing a bronze- 
like surface which practically prevents rust. All the 

methods as yet known for producing a bronze-like surface, by 
rubbing over the surface of the iron an acid solution of cop- 
per or an iron solution, letting it dry in the air, brushing oft 
the rust produced in this way, and an abundant repetition of 
this method, give a more or less reddish-brown crust or rust 
on the iron body. Objects formed of iron can easily be 
covered with copper or brass by dipping them in the requisite 
solution, or by submitting them to the galvanic method. The 
surface so prepared, however, peels off in a short time, by 
exposure to moist air in particular. By the method given 
below it is possible to cover iron objects, especially such as 
have an artistic aim, with a fine bronze-like surface ; it resists 
pretty satisfactorily the influence of moisture, and one is, 
moreover, enabled to apply it to any object with great ease. 
The clean, polished objects are to be exposed to the action of 
the vapors of a heated mixture of hydrochloric acid and 
nitric acid, in equal portions, for from two to five minutes; 
they are not to be shifted, and the temperature may range 
from 300^ to 350^ C. The heating is continued so long that 
the bronze-like surface is well developed on the surface of the 
objects. After the objects have cooled they should be 
well ruboed down with vaseline and again heated until the 
vaseline begins to decompose. When again cold they shouk^ 
be a second time treated with vaseline in the same way.'^ If 
the vapor of a mixture of the two concentrated acicis is 
allowed to act on an iron object in this manner, a light red- 
dish-brown tone is developed. If some acetic acid be mixed 
with the two acids, and the vapor of all the acids together be 



474 

allowed to act on the metallic surface, a fine bronze yellow 
color can be obtained. By using different mixtures of these 
acids every tint, from a dull red-brown to a light brown, and 
from a dull brownish yellow to light brown yellow, can be 
produced on the surface of the iron. In this way son>e 
T-rods for iron boxes were covered with a bronze-like surface, 
and at the end of ten months, although exposed during th-e 
whole time to the action of the acid fumes of a ' b^ratory, 
they had undergone no trace of any change. 

MAIS JFACTURE OF RUSSIAN SHEET IRON. 

There appears to be much misunderstanding in reference 
to the manufacture of sheet iron in Russia, and questions 
are frequently asked the writer : " What are the secrets con- 
nected with it ? " " How is it made ? " " Could admission be 
obtained to the iron works in the Urals, \a here the iron is 
made ? " It is difficult to understand why such questions 
should be asked by persons versed in the literature of 
iron and steel, for Dr. Percy wrote a very excellent and 
accurate monograph on the subject a number of years ago. 

Not having had the opportunity of personally visiting the 
Russian iron works in the Urals, Dr. Percy's paper was com- 
piled from data furnished him by a number of persons who 
had actually visited these sheet iron works. Since it has 
been my good fortune to have the opportunity of seeing 
some of these works in the Urals, but a short time ago, I 
will, at the risk of tellmg an old story, briefly describe the 
process of manufacture as I saw it. 

The ores used for the manufacture of this iron are mostly 
from the celebrated mines of Maloblagodatj, and average 
about the following chemical composition: Metallic iron, 
60 per cent.; silica, 5 per cent. ; phosphorus from o. 15 to 0.06 
per cent. The ore is generally smelted into charcoal pig 
iron, and then converted into malleable iron by puddling or 
by a Franche-Comte hearth. Frequently, however, the 
malleable iron is made directly from the ore to various kinds 
of bloomaries. 

The blooms or billets thus obtamed are rolled into bars 6 
inches wide, ^ inch thick and 30 inches in length. These 
bars are assorted, the inferior ones " piled " and re-rolled, 
while the others are carefully heated to redness and cross- 
rolled into sheets about thirty inches square, requiring from 
eight to ten passes through the rolls. These sheets are twice 
again heated to redness, and rolled in sets of three each, care 
being taken that every sheet before being pas?ed through tb^ 



475 

rolls is brushed off with a wet broom made of fir, and at the 
same time that powdered charcoal is dextrously sprinkled 
between the sheets. Ten passes are thus made, and the 
resulting sheets trimmed to a standard size of twenty-five to 
fifty-six inches. After being sorted and the defective ones 
thrown out, each sheet is wetted with water, dusted with 
charcoal powder and dried. They are then made into pack- 
ets containing from sixty to one hundred, and bound up with 
waste sheets. 

The packets are placed one at a time, with a log of wood 
at each of the four sides, in a nearly air-tight chamber, and 
carefully annealed for five or six hours. When this has been 
completed the packet is removed and hammered with a trip- 
hammer weighing about a ton, the area of its striking surface 
being about six to fourteen inches. The face of the hammer 
is made of this somewhat unusual shape in order to secure a 
wavy appearance on the surface of the packet. After the 
packet has received ninety blows, equally distributed over its 
surface, it is reheated and the hammering repeated, in the 
same manner. Sometime after the first hammering the packet 
is broken and the sheets wetted with a mop, to harden the 
surface. After the second hammering the packet is broken, 
the sheets examined, to ascertain if any are welded together, 
and completely finished cold sheets are placed alternately 
between those of the packet, thus making a- large packet of 
from 140 to 200 sheets. It is supposed that the interposition 
of these cold sheets produces the peculiar greenis>> color that 
the finished sheets possess on cooling. 

This large packet is then given what is known as the 
finishing or polishing hammering. For *^^his purpose the trip- 
hammer used has a larger face than vne others, having an 
area of about 17 to 21 inches. When the hammering has 
been properly done the packet has received 60 blows, equally 
distributed, and the sheets should have a perfectly smooth, 
mirror-like surface. The packet is now broken before cool- 
ing, each sheet cleaned with a wet fir broom to remove the 
remaining charcoal powder, carefully inspected, and the good 
sheets stood on their edges in vertical racks, to cool. These 
sheets are trimmed to regulation size (28 by 56 inches) and 
assorted into Nos. i, 2 and 3, according to their appearance, 
and again assorted according to weight, which varies from 
10 to 12 lbs. per sheet. The quality varies according to color 
and freedom from flaws or spots. A first-class sheet must be 
without the slightest flaw, and have a peculiar metallic gray 
color, and on bending a number of times with the fingers, 
very little or no scale is separated, as in the case >» 



476 

ordinarv sfieet iron. The peculiar property of Russian sheet 
iron is the beautiful polished coating of oxides (* glanz") 
which it possesses. If there is any secret in the process, it 
probably lies in the " trick " of giving this polish. As far as I 
was able to judge, from personal observation and conversa- 
tion with the Russian iron masters, the excellence of this 
sheet iron appeared to be due to no secret, but to a variety of 
conditions peculiar to and nearly always present in the 
Russian iron works of the Urals. Besides the few partic- 
ulars already noted in the above description of this process, it 
should be borne in mind that the iron ores of the Urals are 
particularly pure, and that the fuel used is exclusively char- 
coal and wood. Another and equally important considera- 
tion lies in the fact that this same process of manufacturing 
sheet iron has been carried on in the Urals for the last hun- 
dred years. As a consequence, the workmen have acquired a 
peculiar skill, the want of which has made attempts to manu- 
facture equally as good iron outside of Russia generally 
unsuccessful. It is difficult to understand what effect the use 
of charcoal powder between the sheets, as they are rolled and 
hammered, has upon the quality. It is equally as difficult to 
understand the effect of the interposition of the cold-finished 
sheets upon the production of the polished coating of oxide. 
The Russian iron-masters seem to attribute the excellence of 
their product more to this peculiar treatment than to any 
other cause. One thing is ^quite certain, there is no secret 
about the process, and if the Russian sheet iron is so much 
superior to any other, it is due to the combination of causes 
a-lready indicated. 

THE LARGEST ELECTRIC LIGHT IN THE 

WORLD. 

The largest electric light in the world is on wSt. Catharine's 
Point lighthouse, Isle of Wight. Some idea of the power of 
this light will be conveyed when it is known that the carbon? 
employed in electric arc lamps commonly used fpr street 
lighting are about J^ inch in thickness, while these^have a 
diameter of nearly 2)^ inches. 

. .There are two dynamos,, and if both worked in coiijunc' 
tion it- is computed that the concentrated light; from the 
lantern w^^ld equal six milli<^iis of candles. The indviction 
arrangernent of .each machine consists of sixty permanent, 
ma^ets, and.'each magnet is made up of eight steel plates. The 
armature, 2ft (6/in» in diameter, is composed of five rings with 
twenty-four bobbins , in each., arranged in groups: of four in 
tension and six in quantitar* 



477 



LUMBER MEASUREMENT TABLF. 



LENGTH 


LENGTH 


LENGTH 


LENGTH 


LENGTH 


LENGTH 


2x4 


2x6 


2x8 


2x10 
12 20 


3x6 


3x8 


12 8 


12 12 


12 16 


12 18 


12 24 


14 9 

16 II 


14 14 
16 16 


14 19 
16 21 


14 23 
16 27 


14 21 

16 24 


14 28 
16 32 


18 12 


18 18 


18 24 


18 30 


18 27 


18 36 


20 13 


20 20 


20 27 


20 33 


20 30 


20 40 


22 15 


22 22 


22 29 


22 37 


22 33 


22 44 


24 10 

26 17 


24 24 
26 26 


24 32 
26 35 


24 40 
26 43 


24 36 

26 39 


24 48 

26 52 


3x10 


3x12 


4x4 


4x6 


4x8 


.6x6 


12 30 


12 36 


12 16 


12 24 


12 32 


12 36 


H 35 
16 40 

18 45 


14 42 
16 48 

18 54 


14 19 
16 21 

18 .24 


14 28 
16 32 
18 36 


14 37 
16 43 
18 48 


14 42 
16 48 
18 54 


20 50 


20 60 


20 27 


20 40 


20 53 


20 60 


22 55 


22 66 


22 29 


22 44 


22 59 


22 66 


24 60 
26 65 


24 72 
26 78 


24 32 

26 35 


24 48 
26 52 


24 64 
26 69 


24 72 
26 78 


6xS 


8x8 


8x10 


10x10 


10x12 


12x12 


12 48 


12 64 


12 80 


12 lOO 


12 120 


12 144 


14 56 
16 64 

18 72 


14 75 
16 85 
18 96 


14 93 
16 107 
18 120 


14 117 
16 133 
18 150 


14 140 
16 160 
18 180 


14 168 
16 192 
18 216 


20 80 . 


20,107 


20 133 


20 167 


20 200 


20 240 


22 88 


22 a.17 


22 147 


22 183 


22 220 


22 264 ; 


24 96 
26 104 


24 128 
26 139 


24 160 
26 173 


24 200 

26 217 


24 240 
26 260 


24 288 ■ 
26 312 



A blast at 800 degrees temperature will ignite charcoal ;. 
900 degrees will ignite coke, and 1,300 degrees wiU ignite 
anthracite. 



478 
THE DYNAMO. 

HOW MADE AND HOW USED. 

The interest awakened in machines for the generation of 
current electricity, consequent upon the demand for electric 
lighting and transmission of power, has induced many 
amateurs to turn their energies to the construction of small 
dynamos, such as might replace a battery of eight or ten 
cells, without the disagreeable features of changing acids, 
cleaning plates, etc. Such efforts have not generally met 
with success, owing to the fact that no work of a practical nat- 
ure has yet appeared in which the construction of the 
dynamo is fully explained. When the principles which con- 
trol the manufacture of such machines is understood, 
dynamos can be constructed with as much ease and cer- 
tainty as induction coils. 

§ I. What a Dynamo is. — As understood at present, the 
dynamo-electric machine may be defined as a machine 
whereby energy (motion) is converted into electricty by the 
aid of the permanent magnetism present in certain iron por- 
tions: which electricity is caused to reaet on the iron and so 
heighten its magnetism; and this increased magnetism in its 
turn gives rise to more powerful electrical effects, and so on, 
until a limit is reached, depending partly on the velocity of 
the motion, partly upon the relative apportionments of the 
size and quality of the wire and iron employed in its con- 
struction, and partly on the resistance throughout the cir- 
cuit. Mthough this principle was fully understood, and de- 
scribed by Soren Hjorth, of Copenhagen, in his patents, dated 
October, 1854, and April, 1855, yetthename "dynamo" (from 
dynamis, Qx,^ force) does not appear to have been used in 
this connection until Dr. Werner Siemens employed it in a 
communication to the Berlin Academy, January 17, 1867. 

% 2. Faraday'' s Discovery. — The closeness of the relation- 
ship between the phenomena which we call electricity and 
magnetism had struck many philosophers of the eighteenth 
century. Oersted, of Copenhagen, in 1819, was the first to 
prove, by a series of masterly experiments, the magnetic 
properties of current electricity; Ampere and Arago, in 
France, and Sir Humphry Davy in England, then distin- 
guished themselves by their zeal and activity in this research; 
but the keystone of the arch was laid when Faraday, in 
November, 1831, showed that it was possible to call forth 
electric currents by means of a magnet. In order that the 



479 

reader should have an intelligent knowledge of the principles 
which underlie the construction of the dynamo, it would be 
well for him to repeat some of the experiments about to be 
described, more especially as they are easy of performance 
and trifling in cost. 

The first thing required will be a galvanometer^ an 
instrument for indicating the presence of current electricity 
(and in some cases to measure its quantity). To make this, 
a piece of spring steel, 2 inches long and ^ of an inch in 
width, is "softened" by heating the middle portion ov^»- a 
gas jet or other flame, until red hot, then allow to cool 
gradually. By laying this across a knife blade the exact 
center is found and marked. By means of a screw-arill a 
hole about -^.^ of an inch diameter clear through the center 

of this steel "needle," as it is 
called, is bored. By filing from the 
center toward the side the needle 
is brought to the shape of a 
lozenge, as seen at Fig. i, A. 
Holding this needle by means of a 
piece of copper wire passed 
through the hole, it is heated to 
dull redness over a flame and 
plunged into cold water to restore 
its temper. A piece of brass rod, 
y^ of an inch in diameter, and 
about Yz of an inch long, is now 
soldered centrally, just over the 
hole. This is easily done by 
cleaning the needle with a bit of sandpaper, specially 
round the hole, cleaning also the little piece of brass 
rod, on its end, then putting a little piqce (as big as a grain 
of mustard-seed) of plumbers' solder just over the hole bored 
in the needle. Holding the needle with a pair of forceps (a 
little rosin powder having been previously applied round about 
the hole) over the flame of a spirit-lamp or gas-burner, wiV 
cause the solder to melt and adhere to the steel. The piece 
of brass is now taken up with another pair of forceps, and 
laid (flat side downward) as centrally as possible over the 
hole. Keeping the needle still over the flame, the solder 
will also flow round the brass and adhere to it, making a firm 
junction, when it may be removed from the flame, and placed 
at once on a cold metal or stone surface. It should now 




4^o 

present the appearance shown at Fig. i, B. Any solder 
which may have exuded from between the brass and steel 
should be filed away. Usmg the same bit in the screw-drill 
that was employed originally to bore the hole through the 
steel, a conical hole, reaching nearly but not quite to the 
opposite surface of the brass piece, is drilled from the hole in 
the steel. This serves as a pivot on which to poise the needle. 
A trial may now be made to find whether the needle 
is fairly centered; but no attempt need be made yet to balance 
it if not true. Having cut off the head of a fine-pointed pin, 
drive it, blunt end downward, into the center of a little slab 
of well-seasoned pine 3 inches by 3 inches l)y ^ an inch, 
leaving not less than |^ of an inch protruding. On the point 
■poise the needle, and mark with a pencil the end which 
hangs (if either does). Fig. i, C, will show what is meant. 
The needle must now be magnetized by being allowed to 
remain for some tim.e (twenty minutes or half an hour) across, 
and in contact with the poles of a horse-shoe magnet, care 
being taken that having once placed the needle in one position 
it should not be reversed, as its polarity would be reversed 
ffthis were done; and since in our latitude the 7toj't/i-seekmg 
f He of a freely suspended needle hangs doivnward^ if the needle, 
when tried previous to magnetizing, had one end heavier than 
the other, thatoxi^ must be placed against the north pole of the 
horse-shoe roMgnet, by which means it will acquire south-seek- 
ing polarity, and consequently neutralize to a certain extent 
the inclination of the poised needle. After magnetization 
it should be again poised, any deviation from the horizontal 
line noted am corrected by cautiously filing the needle on 
one of ics fiat sides, at its heavier extremity, with a fine file, 
until perfect equilibrium is obtained. Fig. i, D, illustrates 
the positioa in which the needle should be placed with rela- 
tion Xn the magnet during magnetization. When the needle 
has be^tn) -well balanced it ought to turn very freely on its 
pivot, making several free swings, but finally taking up a 
poDi'don pointing north and south. It should also show de- 
cided polarity when tested with a magnet; that is to say, one 
extremity should be strongly attracted^ and the other just as 
stro7t iy repelled on the approach of the north pole of a 
hors(>shoe or bar magnet. When all these conditions have 
been satisfied, it will be well to mark with a pencil the letter 
N on the extremity of the needle, which is repelled by the 
north seeking (or marked) end of the magnet. This extrem- 



4»i 

ity will be the north-seeking end of the needle, and is gener- 
^ally (though inaccurately) called its north pole. 

{S3. We have now succeeded in making and poising a 
magnetic needle. In so doing we have learned two impor- 
tant facts : {a) that steel becomes permanently magnetic 
when placed in proximity to a magnet; [b] that each pole of 
the new magnet thus formed evinces a polarity of opposite 
kind to that possessed by the pole of the original magnet 
which induced its magnetic condition; in other words, the 
no7'th pole of the orighial magnet induces south polarity in 
that portion of the steel nearest to it, while the south pole 
induces north polarity. 

Our next step is to surround the needle with a coil of in- 
sulated copper wire. To this end a piece of wood 2^ inches 
wide by ij^ inches thick, and of convenient length to hold in 
the hand, is prepared as a form, the edges being slightly 
rounded to admit of the wire being 
slipped off; this is then wound 
with about ten feet of No. 30 silk- 
covered copper wire, as shown at 
Fig. 2, A, leaving about three 
inches of wire projecting at each 
extremity The four corners of 
the rectangle thus formed should be bound with silk, so as to 
prevent uncoiling when the rectangle is drawn off the wooden 
form. The coil, on removal from the form, should present 
the appearance sho\vn at B, in which the ends of the silk 
used to tie the corners are purposely exaggerated in length, 
the better to show their position. The center of the coil 
being found, the wires forming one of the 
flat sides are slightly parted by means of 
a blunt pin (care being taken not to abrade 
the silken covering), and the coil passed 
over the pin-point fastened in the center 
of the little baseboard above described 
(§ 2), and attached thereto with a little 
dab of hot sealing-wax, or, better still, with good elastic 
cement. The needle is then replaced, and tried, to see 
whether it oscillates freely without catching at any point in 
the coil. The two free ends of the wire are now to be de- 
nuded of their silk covering, cleaned with a bit of sand or 
glass paper, and attached to two small binding screws (those 
known as telephone binding-screws, and sold at most elec- 






482 

tricians' av 50 '^ents per dozen, 
will do admirably), inserted 
one at each corner of the base- 
board. The galvanometer or 
multiplier is now complete, 
and should appear as figured at ^'> >• c. 

C. When all is in position, 

note from which binding-screw starts the wire which goes 
over the needle. Mark this binding-screw by writing *' over " 
near it. The galvanometer is used to detect the presence of 
current electricity by causing any such current to pass 
through the coils of the instrument. For this purpose the 
two opposite extremities of any circuit, through which it is 
supposed a current is flowing, are each connected to one of 
the binding-screws. If a current passes, the needle (which 
previously must be made to lie parallel with the coil, by 
turning the baseboard round until the coil points north and 
south, like the needle) will immediately start out from its 
position of parallelism with the coil, and take up a position 
which will approach nearer to right angles with the coil, in 
proportion as the current is stronger. To test whether the 
galvanometer just made be fairly delicate, attach a piece of 
copper wire about 3^3 ^^ ^"^ \xvq)[v thick and six inches long to 
one of the binding-screws; to the other attach a similar piece 
of iron wire. Now bring the free ends of the wire (by bending) 
within y^ of an inch of each other. Turn the baseboard round 
until the north end of the needle points between the two 
binding-screws, perfectly parallel to the coil. Put a single 
drop of vinegar on a little piece of glass, and bring it under 
the two ends of the wires, which must be lowered until 
they are both m the drop of vinegar, but do not touch 
each other. By the action of the vinegar on the two 
metals, an electrical disturbance is set up, which produces a 
so-called" current " which starts from the iron; passes through 
the vinegar, along the copper mre, through the coils of the 
galvanometer, and back again into the iron, this action being 
continuous as long as the vinegar acts on the iron. Simulta- 
neously with this, the needle is seen to deflect from the line 
of the coil, and if our galvanometer i5 a success, it should 
stand out at least 20° from the central line of the coil. Far- 
aday's great discovery, on which all Jynamos are based, con- 
sisted in proving that a magnet could be caused to excite a 
current, similar to that produced by the action of acids on 



4^3 



metals. We can now repeat his experiment 
with the aid of our galvanometer. Let A, 
Fig. 3, be a rod of ^ inch soft iron, about 
6 inches long, bent to the shape of the letter 
U, and wound round its central portion with 
about 100 feet of No. 24 cotton-covered 
copper wire, the two ends of which (about a 
yard each end) having been stripped of their 
covering, must be attached to the binding- 
screws of the galvanometer. If a good horse- 
shoe magnet, B, be placed in contact with 
the two legs of the coiled U, this latter being 
kept motionless, while the magnet is alter- 
nately approached to and separated from 
it, it will be found that the needle of the 
galvanometer is powerfully affected, first in 
one sense and then in the other, according 
to whether we make, or bjrak contact with 
the U, or annaticre, as it is called. . We shall 
also find that, although the most powerful 
effectij are noticed when actual contact and 
actual separation take place, yet currents are 
also produced on approaching or removing 
the magnet to or from a distance. In other words, motion 
in the field of a magnet gives rise to electricity. If we study 
the effects thus obtained, we shall find that they differ in 
some points very markedly from those obtained by the action 
of acids on metals (voltaic electricity — galvanism), inasmuch 
as first, the action is not continuous ; secondly, it is contrary 
in direction when contact is made to what it is when it is 
broken. 

% 4. The student will do well to compare the effects pro- 
duced on the galvanometer by the battery current, and by the 
current obtained from the magnet. Any single cell will 
do for this purpose ; and in order to have an intelligent per- 
ception of what takes place, the student must bear in mind, 
that in the battery itself, the electricity (undulatory move- 
ment of the molecules) passes from the zinc to the negative 
plate (be it copper, silver, platmum, or graphite), while out- 
side the battery, the electricity passes from this latter round 
through the wires, galvonometer, or other circuit open to its 
passage, back again to the zinc plate. (See Fig. 4, where the 
direction of the undulation, or "current," is shown by the 




e04 



arrows ; the plate marked Z being zinc, the one marked C 
being carbon, copper, or other conductor ; W W being the 
wires forming the poles or electrodes. ) If the positive pole (the 
one from which the " current " is flowing, the wire attached 
the C plate) of such a battery be connected to the galva- 
ometer by means of the binding-screw marked " over," the 
ther pole being attached to the other binding-screw, the north 
x)le of the needle having previously been adjusted so as to lie 
jet ween the two binding-screws, it will be found that the 
north pole of the needle will deflect to the left of the 
line of the coil ; the operator being sup- 
posed to be standing at the binding-screw 
end of the galvanometer. Since the wire 
of our coil returns beloiv the needle, it 
is evident that a positive current (an out- 
flow of undulation) passing over the north 
pole of a horizontally suspended needle, 
of a negative current (an influx of undula- 
tion) passing tinder such a north pole, 
causes it to deflect to the left. 

If we disconnect the battery and reverse 
the connections — that is, join the negative 
pole (the wire coming from the zinc) to the 
binding-screw marked " over, " the other pole 
being connected to the other screw — the 
opposite effect results, viz., the north pole 
now deflects to the right of the coil. This 
will be understood by reference to Fig. 5, in 
which a represents the effect of the positive 
current flowing/r^;;/ the operator over the 
needle, the north pole in both illusirations 
being nearest to him; in b the positive 
current is supposed to be flowing from the operator, below 
the needle, in either case returning to the battery the oppos- 
ite way. 

§5. The effect will enable us at once to recognize, by 
means of our galvanometer, the direction in which a current 
is traveling; for, on connecting the two terminals o^ any 
source of electricity to the binding-screws of the galvanom- 
eter, .^while the north pole is in a line with the coik, be- 
tween the two binding-sCrews, the operator facing tie' north 
pole of the needle, it is evident that if the north pole 
oif" the needle is deflected to the left^ the terminal at- 




48s 

tached to the binding-screw marked " over " is positive; but 
that if the north pole deflects to the right, then the 'said 
terminal is negative. It must be borne in mind that by the 
term positive in this connection is meant the point from 
which electricity is flowing, negative being the point toward 
which it is flowing, or at which it enters. This power of 

FIG, C. 




recognizing the direction of a current will be found of greal 
service to us in the construction of the dynamo. 

§ 6. Returning now to our experiments with the magnet 
(see latter portion of § 3), and using in preference a straight 
soft iron rod, about 6 inches in length and yi inch in diameter. 



4^6 

coiled with about loo feet of No. 24 covered wire as our 
armature, and a good bar magnet to produce the electrical 
effects, we shall find, on coupling up the armature wires to 
the galvanometer, and approaching one end of the armature 
to or receding it from the north pole of the magnet, that the 
electrical flow set up is always in one direction in approach- 
ing or making contact, and in the opposite direction on re- 
ceding or breaking contact. Fig. 6 will make this clear. 
The arrow at a shows the direction of the current produced 
on approaching or making contact with the north pole of a 
magnet; b illustrates the direction of current produced on 
receding from or breaking contact with the north pole of a 
magnet. If now we reverse the experiment by presenting the 
south pole of the magnet to the coiled armature, we 
shall find that the direction of flow is also reversed; that is 
to say, the withdrawal of a south pole produces the same 
effect as the approach of a north pole, and vice versa, the 
approach of a south pole is equivalent in its effects to the 
recession of a north pole. It must be noted that the direction 
in which the wire is coiled round the soft iron rod (or arma- 
ture), while it has no influence on the direction of the elec- 
trical c^carent set up round the iron rod (which is always the 
reverse to the hands of a clock in the face approaching the 
north pole) determines the extremity of the said wire at 
which the current leaves or enters the coil. In the figure 
we have supposed the wire to be wound from left over 
toward right ; had we wound our rod from left under 
toward right, the opposite ends of the wire would have been 
respectively + and — . This must be borne in mind when we 
proceed to actual work. 

§ 7. Currents can produce Magnetism, — If we take the 
coiled soft iron U, of which we made use § 3, and apply it to 
pieces of soft iron, nails, filings, etc., we shall find that it 
possesses little or no magnetic power of attraction; bu.t if 
we couple the projecting ends of the coiled wires one to each 
terminal of a single-cell battery, we shall find that the U will 
become powerfully magnetic, retaining its magnetism as long 
as electricity flows around the coils, but losing nearly all the 
instant that the flow is caused to cease, either by breaking 
connection with the battery or by any other interruption. 
The rapidity and completeness with which the iron loses its 
magnetism depends almost entirely on its softness and ptwity. 
Anything which tends to put a strain on the molecules of the 



^3- 



48? 

iron, such as hammering, filing, twisting, sudden cooling, 
vibration, etc., render it liable to retain magnetism, or 
increase its coercitive force ; whereas raising to a high tem- 
perature and very gradual cooling, which allows the mole- 
cules to range themselves with little or no strain, furnishes a 
soft iron, eminently incapable of retaining magnetism, or 
possessing little coeiritive force. 

% 8. The direction in which the flow of electricity 
takes place around the iron bar decides which end of the 
bar acquires nortk-seekijig, and which south-seeking po- 
larity. Let us suppose as in Fig. 7, A, that one ex- 
tremity of the bar be made to face us, and that the 
current be caused to flow in the direction of the motion 
of the hands of the clock; in this case, the farther ex- 
tremity of the bar becomes a north-seeking pole, while the 
nearer extremity becomes south-seek- 
ing. The direction of the current, 
and consequently the polarity of the 
bar, may be reversed by joining up 
the ^//^j"//^ electrodes of the battery 
(or other source of electricity) to the 
ends of the wire coiled round the bar, 
as shown at B; where, as the wire is 
joined to the electrodes in a manner 
just the reverse to that shown at A, 
so also the current enters at the op- 
posite end of the wire, and produces 
\^ contrary magnetic effects. The same 
result may also be attained by coiling 
the wire around the bar in the con- 
trary direction, while leaving the 
connection with the electrodes un- 
changed, as represented at C (Fig. 7«). Perhaps the simplest 
means of remembering the relation 
which exists between the direction of rto t* 

the current and the position of the 
magnetic poles produced, is oneknown 
as " Ampere's Rule," in which the ex- 
perimenter considers himself to be 
swimming head foremost, ivith the 
current, along the wire, always facing 
the iron core; then the NORTH-seek- 
ING roLE will always be at his left hand. (See Fig. 8). 






488 

§ 9. It must be borne in mind, as 
p • being of the greatest importance in 

^* ^ the construction of successful dyna- 

mos, that although steel, or hard 
iron, when subjected to this induc- 
ing action of the current, becomes 
magnetic, yet it does not acquire 
nearly such powerful magnetism as 
soft iron; and, in fact, the softness 
of the iron, and its capacity for be- 
coming powerfully magnetic, run side by side. On the other 
hand, it must not be forgotten, as we learned at § 7, that the 
softer the iron the sooner it loses the magnetism imparted to 
it; while the harder brands of iron (and more especially steel) 
retain nearly all the magnetism which it is possible to confer 
upon them. 

§ 10. The student who has carefully and intelligently 
performed the experiments described in the previous sec- 
tions, will now find himself in a position to understand the 
principles which underlie the ponstruction of the dynamo, 
even though he may have little \^x no previous knowledge of 
electricity. The first machine constructed after Faraday's 
discovery was that of H. Pixii, in 1832. In this machine 
a powerful horse-shoe magnet was caused to rotate rapidly 
before a soft iron U-piece, wound with insulated cop- 
per wire, the two extremities of which were prolonged by two 
brass springs pressing against a rotating split collar of brass, 
whose office was to rectify the direction of the currents pro- 
duced by rotation of the magnet, before the iron core; cur- 
rents which, as we have set. (^ 4), are in different directions, 
according to whether a given pole of a magnet is appi^oaching 
to or receding from the core. This arrangement for causing 
alternating currents to flow in one direction, is known as 
the commutator, and it, or some modification of it, is most 
extensively used in all dynamos in which it is of importance 
that the current should flow in one direction only. The 
chief disadvantage in this machine was that of having to 
rotate a heavy magnet (built up of a number of thin steel 
plates), since the mere rotation tended to destroy, or at all 
events, to weaken its magnetism. In 1833 Mr. Sexton had 
the happy idea of fixing the heavier and causing the lighter 
portions of the apparatus to rotate: in other words, the 
magnet (or magnets) was now made a fixture, while the U- 



4^9 

shaped soft iron armature, with its surrounding coils of wire, 
was caused to rotate rapidly before it, on axis or spindle, 
either by gear-wheels or wheel and band. Mr. E. M. Clarke, 
:n 1834, noticed that the thickitess of the wire coiled round 
the armature had a considerable mfluence on the nature of 
the current produced by these machines. If the wire em- 
ployed be very thin, say about the yf,(. of an inch in diameter, 
and a large number of convolutions be coiled around the 
legs of the armature, the electricity produced is of high 
tension, capable of overcoming considerable resistances, and 
of giving severe shocks. If, on the contrary, a smaller 
quantity of a much thicker wire, say from the ^r to the ^^ 
of an inch be made use of, the current produced is that 
.cnown as a quantity cttrrent, o>* a " large " current, possess- 
ing but little power of overcoming resistances, not capable 
of giving shocks, but giving fine large sparks- and able to de- 
compose water, and other chemical bodies. Jlarke usually 
furnished two armatures with his machines, one wound with 
about 1,500 yards of covered wire ^-^ of an inch in diameter, 
which he designated the " intensity " armature; the other, 
wound with about 40 yards of wire --^^ of an inch thick, to which 
he gave the name of the " quantity " armature. One pecu- 
liarity of the machines turned out by Clarke was the fact ot 
the rotating U-shaped armature being made to rotate near 
the flat sides of the magnet instead of in front of the poles. 
This, though it facilitates somewhat the mechanical arrange- 
ments, is open to some objections 
on the score of lesser efficiency, since 
the most active portion of the mag- 
net is certainly in front of the poles. 
As Clarke's machine embodies near- 
ly all the principles found in later 
dynam.os, we shall give an illustra- 
tion, together with detailed explana- 
tion of the commutator, etc., in our 
next paragraph. 

§ II. In Clarke's machine the 
horseshi^v? magnet. A, Fig. 9, is 
clamped to a rigid backboard, which 
is mortised to the baseboard. In 
front of this magnet, and in close proximity to its poles, is the 
armature B B', which can be made to rotate on its axis at 
-<*, which passes right through the backboard, behind which 




/3C 




it is supported on bearings. The distant end of the axis ; 
fitted with a pulley, around which plays a band or gut coming; 
from the fly-wheel f. On turning the handle of f^ the 
small pulley enters into rotation, carrying with it \\\t 
armature. This armature (which represents the U-piece 
described at "J 3, Fig. 3) is really constructed of three 
pieces of very soft iron, two short 
circular bars and a cross-piece, held /^ ^q 

together by screws, as shown at <^. 
Around the two bars is carefully 
coiled the insulated* copper wire, 
m such a manner that, if the bars 
were straightened out, the winding 
would be always in one continuous di- 
rection,either from left over to rights 
or vice ve7'sd^ and the two extreme ^^ „ 
ends of the wire are brought out ^^^ 
and joined metallically with the two 
metal half-cylinders which form the 
commutator c. This commutator 
is illustrated more fully -at Fig. 10 

r. Against the commutator press the two brass springs ^and 
d\ to which are connected the wires e and e\ which form the 
real electrodes or poles of the m? chine. Fig. 10 shows how 
the wire is wound round the two soft iron cores B and B', which 
are screwed to the soft iron cross-piece at A and \', thus con- 
stituting virtually a coiled U-piece. The two ends of the 
wire which forms these bobbins come out at opposite sides ot 
the bobbins, and are soldered or screwed to the half-cylinders 
(of brass) c and <:', as shown at b and b' . In order that the 
two cheeks of the commutator, c and c' (which are shown sep- 
arately to the right-hand of Fig. 10), should not allow the 
electricity to escape from one to the other, the spindle which 
carries the bobbins B B' and the cross-piece A A', is encased 
in a thick ring of ivory, baked boxwood or other insulator, 
which in the illustration is shaded darkly. 

Function of the Commutator. — % 12. If we follow 
one of the bobbins of the armature durmg its revolution be- 
fore the poles of the magnet, we shall find that it change? its 
magnetic condition, and consequently its electrical state, iwice 
viurmg each revolution. Let us take, for instance, che bob- 

* A body is said to be insulated when surrounded by substances 
which prevent the passage of electricity. 



bin B' in either figure in its rotation from the north pole of 
the magnet toward the south pole, as we learnt at ^ 6, /eav- 
ing a north pole or approachijig a soutli pole produces the 
same effect; and this effect will be that a current will flow 
round the bobbin from the right over toward the left. Hence, 
if the wire (which is coiled round the bobbin in the same di- 
rection) have its corresponding extremity joined to any cir- 
cuit, this extremity will be found to be negative. In practice 
this extremity is actually connected with the cheek c' of the 
commutator. This cheek c' during the whole of the semi- 
revolution of the bobbin B' from north to south, is being 
pressed against by the spring d' ^ which, with its wire e\ is 
consequently kept continuously in a negative state until the 
bobbin B'' has arrived quite opposite the south pole of the 
magnet. At this instant the spring d' touches neither of the 
brass half-cylinders, but presses against the ivory, boxwood, 
or other insulator, which separates the two half-cylinders of 
the commutator c and c' , Hence, no current flows; but di- 
rectly B' leaves the middle of the south pole and begins to 
complete the under half of the revolution, its cheek comes 
into contact with the spring on the opposite side, </. But. 
now we find that the bobbin B' is leaving a south pole to ap- ' 
proach a north pole; therefore, according to % 6, the current 
is flowing in the opposite direction round the bobbin. There 
fore the spring d collects from the cheek c' positive electricity. 
AVhat has been said of bobbin B' is, of course, equally true of 
bobbin B at similar points of its revolution; hence we see that, 
although each bobbin becomes alternately north and south as 
it approaches the south or north pole of the permanent magnet, 
and sends therefore a current alternately in contrary direc- 
tions, yet, since (owing to the insulated half- cylinders) we 
are able to cause one spring to pick up the current from the 
bobbnis whilst the free extremity of their encircling wire is 
sending a positive current only (the other spring picking up 
the current only whilst the free extremity of the coiled wire 
is negative), it follows that the springs d and d' are main- 
tained in oppositely electrified conditions. It must be borne 
in mind that the wire is coiled continuously round both bob- 
bins; hence, that as the bobbins are always exposed at the 
same time to opposite magnetic influences, so the conditions 
of the two extremities of the coiled wires are electrically 
opposite — viz., while one is positive the other is negative^ 
and vice versa; but that as the bobbin, whichever it be. 



492 

which travels from north over to south has the free extremity 
of its wire always negative and in connection with the spring 
d\ while the bobbin (each in tm-n) which passes under 
from south to north has its extremity always positive and in 
connection with the spring d' it follows that, providing 
always the motion be that indicated by the arrow in Fig. lo, 
the spring d' wdll always be kept in a negative condition, 
while the spring d will simultaneously be positive. 

Since the comprehension of the function of the commuta- 
tor is of the highest importance in the manufacture of the 
dynamo, we recommend the amateur to digest carefully the 
contents of this last section. 

§ 13. The next great step in the development of the 
dynamo was the application of the current generated by the 
armature to the heightening of the magnetism of the magnets 
which set up that current in the armature. We have seen 
(§7) that a current sent round a mass of soft iron converts 
that iron into a magnet ; and we find that the intensity of 
magnetization is, up to the point of saturation, proportionate 
to tiie quantity of electricity flowing round the iron. We 
also know that magnets produced by such means (that is, the 
passage of currents arou7id soft iron cores) are much more 
powerful than permanent steel magnets of equal size and 
w^eight Hence, apart from the question of less expense and 
greater constancy (for steel magnets gradually lose their 
power by the continuous motion of the armatures before 
their poles), there is actually a great gain in efficiency in em- 
ploying electro-viagnets instead of permanetit 7Jiag7tets 
wherewith to induce the current, in Hjorth's machine 
(which was perfected so far back as October, 1854) 
two compound cast-iron magnets A A (Fig. ii), which 
may or may not be surrounded by a coil of wire, are 
bolted to the frame of the machine. These magnets 
are shaped like the letter C ; and in the gap between 
the poles rotates a wheel, B B, on the circumference of 
which are fastened several armatures consisting of soft iron 
cores wound with insulated copper wire, the ends of which 
are brought out to a peculiarly constructed commutator, 
which rectifies the dissimilar currents produced. The wheel 
(and consequently the armatures) is caused to rotate by 
means of the rigger C and driving-axle. Around these 
movable armatures, and also bolted to the frame, are several 
soft iron cores wound with insulated copper wire, D D D D. 



493 

The currents produced in the first instance by the passage of 
the armatures before the poles of che magnets, A, after being 
rendered uni-direction by means of a commutator, are led on 
through wires to the coils which surround the soft iron 
cores, D D D D. These become, therefore, powerful 
electro-magnets, and induce in their turn more powerful cur- 
rents in the armatures. The larger currents thus produced, 
again reacting in their passage on the electro-magnets, super- 
induce a higher state of magnetism in them, and this again 
exalts the electricity generated in the armatures, and so on 
until the limit of saturation is reached. The current, after 
traversing the coils, is led to terminals to which connection 
can be made for exterior w^ork. 

It is remarkable that, although this discovery was so 
important, and the description and designs were so clear in 
the specification, so little attention should have been attracted 
to it. Soren Hjorth was, indeed, much before his time, 
many of the machines now doing excellent work . being 
simply trifling modifications of his " magneto-electric bat- 
tery." 

§ I4.'^rhe intensity of electric and magnetic effects does 
not increase in the simple proportion of the nearness of the 
bodies acted on, but in a much greater ratio, which, in the 
case of electrified bodies and permanent magnets, is directly 
as the square of the nearness, or (what amounts to the same 
thing) \'s>inversely as the square of the distance. For instance, 
we find that a magnet which exerts a " pull " of i lb. on a 
given piece of iron at 6 inches, if placed at 3 inches, or twice 
the nearness, pulls with a force of 2 X 2 == 41b.; and if placed 
four times as near, namely i^ inches, pulls with a force of 
4 X 4 = 16 lb. 

p ,^, It would appear that in the case 

of electro magnets the ratio between 
the distance and the effect increases 
even more rapidly, being, according 
to the best authorities, equal to in- 
versely the cube of th^ distance nearly. 
Hence it struck Dr. Werner Siemens, 
of Berlin, that if the armature could 
be constructed of such a form as to 
allow of its remaining always very 
close to the poles of the magnet 
during its rotation, greatly exalted electrical effects would 




494 

-L^sult; and in 1856 he patented in this country the special 
?rm of armature represented at Fig. il a, so well known as 
.lie "Siemens" or "H -girder" arrnature. On reference 
tO the armatures depicted at Figs. 9 and 10, it will be seen 
that during a considerable portion of their rotation they are 
at some distance from the legs of the magnets, and even 
when near them are not at the points of greatest action. 

On the contrary, the Siemens armature is placed as 
nearly as possible at the most active portion of the 
magnet's poles — viz., their extremities, and at every por- 
tion of its rotation some portion of the armature is ex- 
posed to the action of the said poles. The Siemens arma- 
ture, as shown at Fig. 11 a, consists of a cylinder of soft iron 
between three and four times as long as its diameter, around 
the sides and ends of which is cut a deep groove or channel, 
rather more than one-third the diameter of the cylinder. 
This is shown in section at d. The soft iron cylinder c, has 
brass heads and axes fitted to it as shown 9 1 f and g — the 
latter carrying a pulley or rigger^ by which the armature can 
be rotated; while the former is encircled by the commutator 
e e^ to which are attached the two ends of the insulated wire, 
which is wound in the channel. When in action this arma- 
ture is placed between the poles of a 
compound horse-shoe magnet, and 
supported on trunnions or bearings at 
both ends; two springs pressing against 
the commutator carry off the electric- 
ity generated by the rotation of the 
armature, the motion being imparted 
by means of a band passing over the 

pulley at the farther end of the armature. A general idea oS 
this arrangement may be gathered by inspecting Fig. 1 1 il. 

Currents given by these Machines not continuous. 

^ \^, Since the direction of the current changes at every 
semi-revolution of the armature in such machines as those of 
Clarke, Pixii, and Siemens, and at every passage of the com- 
pound armature before the poles of the inducing magnets in 
Soren Hjorth's machine, we are constrained to use a com- 
mutator whenever we desire to produce a current in one di- 
rection only. But the commutator, by the very fact of its 
^eing necessarily constructed of two or more portions of ^ 
aietallic cylinder, separated by intervals of insulating m^ 




495 

terial, interrupts the passage of the electricity every time that 
the springs press against the insulating spaces. Hence the 
electricity furnished by these machines partakes more of the 
nature of rapidly succeeding waves, than of a steady continu- 
ous current, like that furnished by the battery. Still, when 
the armature is rotated at a high speed (and the Siemens re- 
quires to be driven at about 3,000 revolutions per minute, to 
give the best effects), these waves succeed each other with 
such rapidity as to simulate a steady current, no break in 
continuity being perceptible to ordinary tests. 

Rapid Magnetization and Demagnetization produces 

Heat. 

^ 16. It is found that the sudden change from north magnet- 
ism to south magnetism, which takes place in each half of the 
above described armatures, as they pass over from before a 
south pole to before a north pole of the inducing magnets, is 
accompanied by a very considerable rise in temperature; and 
that this rise increases with the rapidity of change of magnetism, 
which in its turn depends on the rapidity of rotation. So 
marked is this rise of temperature, that a dynamo fitted with 
a Siemens armature of the pattern figured at § 14, and started 
at an initial temperature of 10^ C, rises in about twenty min . 
utes to nearly 50^ C, when driven at 3,000 revolutions pei 
minute. This rise in temperature is detrimental to the effi. 
ciency of the machine: — ist. Because the wires of the arma- 
ture, becoming heated, conduct less freely; hen^e "^oss of 
current. 2d. Because the armature itself is not capable of 
such intense magnetisation when hot as when cold (a red-hot 
mass of iron is hardly affected by the magnet); hence another 
loss of current. 3d. Because the insulating covering of the 
wire is impaired, if not actually ruined, if the temperature 
exceeds a very moderate limit. 

For these reasons it is important to keep the temperature 
of the armature as low as possible. The first successful step 
in this direction was taken by Dr. Pacmotti, of Florence, in 
i860, who constructed an armature of soft iron, in the shape 
of a ring around which were coiled, in successive sections, 
helices of insulated copper wire, the ends of which were 
joined up to a divided ring commutator The ring armature 
of soft iron, with its covering of wire, was supported on a 
central axle, and rotated before the poles of a magnet, either 
permanent or electro. At no part of the revolution is ^ich 



49b 

a ring taken as a whole farther from, or nearer to, the poles 
of the magnet; and although its magnetism is constantly 
changing, yet the change is not abrupt, but gradual and con- 
tinuous; as will h^. explained in the following paragraph. 

Pacinotti's Ring Armature. 

§ 17. The descilption and illustration of this machine is to 
be found in the Niiovo Cimento for the year 1864, under the 
heading of " Una Descrizione d'una Piccola Macchina Elettro- 
Magnetica." The machine itself, as described, can be used 
either as a motor, or as a generator of electricity; and its 
adaptability to either purpose was specially dwelt upon by 
Dr. A. Pacinotti, in his communication; but it is only under 
the aspect of a generator that we shall stop to consider it 
here. 

Two electro-magnets, S, N, Fig. 12 (which may, or may 
not, be united together below), 
are fastened to a baseboard, and 
so arranged that the upper ex- 
tremity of one is a north pole, 
while the other is a south pole. 
These poles are furnished with 
semi-circular prolongations B B, 
B' B', between which is poised, 
on the axis C D, a soft iron ring 
A A. This ring is attached to 
the axis by means of radial arms. 
Coils of insulated wire are 
wrapped round the ring at short 
intervals about its periphery, the 
end of each coil being brought down the axis at D and at- 
tached to one of the small copper strips at E (of which there 
are as many as there are coils around the ring), the wire 
beginning the next coil being also metallically connected to 
this same strip. The wire terminating the next coil is 
fastened to the next strip, from whence starts a fresh coil, 
and so on, until all the strips, which form the compound 
commutator E are connected to the coils in. such a manner 
thai the end of one coil, by its attachment to its strip, forms 
the commencement of the next. Consequently, the wire 
forming the coils, although capable of communicating electri- 
cally with the springs F F at opposite points of the diameter 
of the coromutator, is really continuous. The ring A A ij. 




^iq 12, 



497 

caused to rotate by means or the rigger G and the driving 
belt H. 

It will be evident on reflection that the half of ring oppo- 
site the pole marked N will acquire by induction south 
magnetis7n^ while the half facing the pole S will for a similar 
reason become north. Hence the ring, w^hether in motion 
or at rest, will, provided the electro-magnets be active, become 
a circular magnet, with the south pole facing the north pole 
or the electro-magnet, and its north pole facing the south 
pole of the electro. When the ring is rotated, though if 
viewed as a whole, this magnetic condition remains unaltered, 
yet, of course, any given portion of the ring will gradually 
change as it passes over from one " horn " or prolongation of 
the magnets to the other). Still, the change which takes 
place is not abrupt, but gradual, and partakes more of the 
nature of a wave than oi shock. So also, since the springs of 
the commutator press on several strips at the same time, at no 
time is contact ever entirely broken between the commutator 
and the springs; therefore the current which is produced as a 
contmuous wave, ahvaysin one direction^ is collected in a sim- 
ilar continuous manner by the springs F F, and may be em- 
ployed where required by coupling up the wires I I. 

This machine, discovered more than twenty years ago, em- 
bodies all the essential characteristics of the best modern 
machines, and the much vaunted machines of Gramme, Brush, 
Siemens- Alteneck, Maxim, Edison, etc., are, at best, but 
trifling modifications of the Pacinotti ring machine — modifica- 
tions which have not always been improvements. Having 
now brought our brief sketch of the essentials of a dynamo 
to a close, we shall proceed in our next section to construct- 
ive details. 

The Patterns. 

§ i8. In the dynamo we are about to construct, three sepa- 
rate pieces for patterns are absolutely necessary — viz., one for 
the armature, one for the legs of the field magnets, and one 
for the standard which supports the fly-wheel. There is no 
necessity for the amateur to put himself to the trouble of cut- 
ting out a pattern for the flywheel, since such wheels with 
handles already fixed can be had for a dollar or so. In con- 
structing the wooden patterns, from which the iron castings 
are afterward to be procured, the amateur ^. juld remember 
to cnoose^ry, well seasoned wood, free from knots. Red 
pine, for such small work as is required, will b^ found Z3 



498 

good as ^ny. Any joints that are absolutely necessary (and 
joints skould be avoided as much as possible) should be at- 
tached together with dowels and glue. It must be borne in 
mind tha the molder places the patterns in green (moist) sand, 
and that ihismoisture causes ordinary glued joints to come un- 
done or e3\ >and. Any roughnesses left on the pattern also swell 
up, catch t^^^ sand, and thus destroy the sharpness and beauty 
of the m<)\ \ and therefore of the resulting casting. It is 
therefore advisable, after having got the wooden pattern 
to the hignest possible degree of smoothness and true- 
ne^s by means of emery-paper, etc., to give it a coating 
of melted paraffine wax, and polish the surfaces carefully 
with a roll of flannel. This renders the surfaces not only 
extremely smooth but impervious to moisture, so that the pat- 
tern does not warp or swell when placed in the sand. In 
order that the pattern should come clean out of the sand and 
not break away any portion of the mold, care must be 
taken that the edges be slightly rounded, so as to give whg,t 
is technically called clearance. The possessor of a lathe can 
turn up many portions of the fittings with much greater accur- 
acy and rapidity than one provided with only ordinary tools ; 
but in the ensuing directions the amateur is supposed to pos- 
sess tools of the simplest kind only. 

§ 19. The pattern for the aj-matiirc first demands our at- 
tention. When completed, it presents the appearance shown 
at Fig. 13, a being the elevation and b the section, on a scale 
of about half the real size, and consists of a wooden cylinder 
i^ inches in diameter by 3;^ inches in length, with a deep 
channel round the ends and sides. To construct this pattern, 
procure a piece of pine 8 inches long by i^ inches wide and 
% of an inch thick. Lay this on a table on its widest side, 
and draw a line along its whole length, that shall divide it 
into two halves of ^^ of an inch each. Now, draw a line on 
each side of this central line, rather better than y% of an inch 
from it. Holding a metal rule against one of these sidelines, 
with a sharp penknife, cut into the wood along the line to a 
depth of about y% of an inch — rather less than more. Now, 
perform the same operation on the other side line to the same 
depth. With a sharp ^ inch chisel, shave away the wood 
on the outside of the cut lines to the depth of y% of an inch 
on the outsides, but rising up very slightly toward the center, 
as shown at Fig. 13, c. This precaution will ensure the 
pattern lifting out clear from the mold. 



500 

Now, take a piece of stout cardboard, and with a pair of 
compasses strike out a circle i^ inches in diameter. Cut the 
circle out of the cardboard so as to leave a clean circular 
aperture of the diameter specified. This is to serve as the 
teviplct, or gauge, of the size and general truth of our arma- 
ture. Strike out, also, in a similar manner a circle in 
a piece of stoutish zinc, or tinned iron, also ij^ inches 
in diameter, and cut this into halves (one of which is shown 




■at dy These will serve to shave away the last irreg- 
ularities from the wood, when it has been roughly trimmed 
up to the shape shown at e^ by means of a small plane, or 
penknife. The piece may now be cut into two halves across 
its length, doweled and fastened together with glue, and cut 
down to the exact length required — namely, 3^ inches. 
All roughnesses should now be carefully sand-papered, and 
care should be taken that the finished pattern should pass 
exactly through the cardboard pattern, being apprecial}ly 



50X 



neither thicker nor thinner at any part. When this has been 
effectea satisfactorily, a small quantity of paraffine wax (a 
piece of paraffine candle will do) should be melted in an 
iron spoon, and well rubbed into the pattern at all points 
with a roll of flannel until it is thoroughly impregnated with 
the wax; rubbing the pattern until it acquires a polish com- 
pletes the operation, and renders it ready for the founder. 
The thin central portion, which joins the semi-circular por- 
tions, should be about 2^ inches in length, having radier 
more than ^ an inch cut away at each end, so that the chan- 
nel is continuous round the armature, being ^ of an inch 
wide and about ^ an inch deep all round. 

§ 20. The pattern for the legs of the electro-magnet (field 

mag7tets, exciting viagnets) wiD 
next require our care. Since 
the two legs are exact counter- 
parts, the one of the other, so 
we need only make one pattern, 
from which, however, two cast- 
ings must be obtained. Fig. 14 
illustrates the form and dimen- 
sions of this pattern on a scale 
of about one-quarter the real 
size. The dimensions are 
marked in inches. A represents 
the outside view, i.e.^ as seen 
from the side which is farthest 
frcm the armature; B gives the 
view from the inside (close to 
which the armature rotates). 
To make this pattern, procure a piece 
of pine 6 inches in length, 4 inches in 
width, and ^ an inch thick, planed smooth, 
and free from knots and roughness. Glue 
the dowel along the bottom edge a strip 
1]/^ inch wide, 4 inches long, and ^ of 
an inch thick, as shown at Fig. 15, a. 
Now, with a sharp plane, remove half 
the inner edge, as shown at Fig. 15, <^, 
so that it makes an angle with the edge 
of the 6-inch piece. With a fine saw 
cut a recess on each side of the jointed 
piece V/i inclies long by 4 inches deeOj 





502 

as shown at <:, and glue and dowel in each recess the two 
flanges, made of ^-inch stuff, of the shape and dimen- 
sions given at d. To insure the slot e being exactly at the 
same point in each flange, the two flanges, after being roughly- 
shaped with a fretsaw, or other wise, should be clamped 
together, and the finishing touches given with a rat-tail file, 
for the slot ^, and with sandpaper along the rounded edges. 
Care must be taken that these flanges should be a trifle thin- 
ner near the edge marked \% than on the opposite edge, to 
insure the pattern coming out clean from the mold. For 
this reason the slot e must not be narrower at the outside 
than at the inside, but rather the contrary. The slot e must 




be % of an inch wide, and must reach in depth to the 6-inch 
piece, to which the flanges are attached. At this point our 
pattern will present somewhat the appearance shown at/. A 
piece of wood 4 inches long hy Ij4 inches wide, and X ^^ 
an inch thick, perfectly smooth, square, and free from knots, 
must now be chosen, and the two sides planed away, on the 
upper side to such an extent as to make an angle of 60° with 
the base. (See Fig. 17, a.) With some good, thin, hot glue 
this piece is to be glued along the bottom edge of the 6-inch 
piece, on the side opposite the flanges, and in such a manner 
that the slope of the base is continued by the slope of the 
piece, as shown at Fig. 17, d. When the glue is quite dry, 
by means of an inch gouge, cautiously hollow out along the 
entire length of this piece, in a simicircular form, nearly to 



5-'3 

the depth of the original 6-inch piece, so as to fit accurately 
the pattern of the armature which has already been made. 
{^ 19.) When this is as trup and smooth as it can be made 
with the gouge, fold a piece of fine glasspaper over the pat- 
tern of the armature, rough side outward, lay the armature 
in the channel, and work it backward and forward until per- 
fect smoothness and a perfect fit are insured. The pattern 
should now present the appearance given at Fig. 17, c. 
When this end has been attained, four small dowels should 




be inserted into the thicker portions of this semicircular piece, 
to hold it firmly down to the 6-inch piece. We now need 
only make the top flange, by which the bracket or stand- 
ard that bears the wheel is clamped to the legs of the dyna- 
mo. This is made most easily in two pieces, one being 
squared up to 4 inches long, ^ of an inch thick by ^ of an 
inch wide. The other piece is to be Ys of an inch thick, 
and must be cut into a perfect semicircle, with a radius of 
1)4 inches. By means of glue and a couple of dowels, this 
is neatly attached to one side of the other square piece, as 



504 

illustrated at Fig. l*] d, and then the whole is carefully and 
squarely glued and doweled, in like manner, to the top of the 
6-inch piece, so that it now presents the appearance shown at 
A and B, Fig. 14. The holes shown in the bottom and top 
flanges may be bored, and core prints inserted, if the founder 
will take the trouble to put them in his mold; but, as a rule, 
founders do not care to cast small castings with holes in 
them, as they seldom come true, so that it will be, perhaps, 
as well to have them bored afterward, which can be done at 
a small cost. This pattern must now be carefully smoothed, 




Fig it 




*v.. 



the sharp edges rounded, to insure parting from the mold 
and iinally parafined arid polished, as recommended for the 
armature (§ 19), when it will be ready for the molder. 

§21. The next pattern to be made is that of the 
standard^ which supports the driving-wheel. This should 
be made out of 34^ -inch stuff, a piece of which 5X inches 
long by 2% inches wide must be cut to the shape shown 
at A, Fig. 16* (one-quarter the real size). In order not to 
split the top while boring the hole, it is as well to bore the 
hole (which should be y^ an inch in diameter) before shaping 
the piece. For the same reason, the piece marked C, which 
should be ^ an inch thick and i inch in diameter when fin- 
ished, should be glued to the center of the top end of the piece 
A, and the whole bored (by means of a brace and sharp ^-inch 



505 

center-bit) oefore trimming up to shape. From the sarxie 
54^ -inch stuff, another piece, figured at B, is cut out, being 
)^ an inch wide at the top, sloping gradually, and becoming 
wider to about half its length {c/) when it should sharply 
curve to a width of 4 inches. The length of this piece should 
be 5 inches, and it is to be glued and doweled to the center 
of the piece A, close against the boss C, as shown at B. A 
small piece e must now be glued and doweled to the edge of 
the curved flange, so as to make it flush with the front A. 
When this has been smoothed and polished with parafline, the 
patterns are ready for the foundry. The three holes shown 
at cf may be bored in the castings. 

The Castings. 

§ 22. The patterns may now be sent to the foundry, with 
the following instructions: First, the armature should be 
carefully annealed, so as to constitute a 7nalleable ii^on casting; 
second, two legs should be cast from the pattern shown at 
Fig. 14, and these also must be carefully annealed,. and be 
made as soft as possible; third, the standard (Fig. 17, B) 
will be better if left pretty hard, as in this way it will retain 
sufficient magnetism to start the machine without adventiticjs 
aid. Particular stress must be laid on the importance of the 
iron in the armature and legs bemg very soft, since much of 
the efficiency of the dynamo will depend on this point. ^See 
§ 9. ) When the castings return from the foundry, their 
degree of hardness may be tested by trying with a rather 
coarse file. If the file bites easily, the iron is fairly soft; if 
it slips over without filing, it is altogether too hard. (This 
does not apply to the standard, which may be left quite hard 
without any detriment to the machine). The armature must 
now be cleaned and trued up. If the student be the happy 
possessor of a lathe, this will not prove a difficult job; if other- 
wise, he may, by careful fihng, remove any irregularities, and 
square up the ends. These must be made quite true; other- 
wise it will be impossible to center the armature so as to 
rotate it between the poles of the magnet. The thin central 
portion shown at a. Fig. 13, and there marked 2^, must 
have its edges rounded, so as not to cut the wire, which will 
have to be wound round it. No trouble should be spared to 
get the armature as truly cylindrical as possible; as care ex- 
pended at thisportionof the process will render the remainder 
of the work very much easier, and more satisfactory. The 



500 

armature having been thus rendered true, the legs will demand 
our attention. Having gone over the surface with a bastard 
file to remove any irregularities, the curved channels, shown 
at A and B, Fig. 14, must be carefully cleaned out. Perhaps 
the quickest way to do this, and to clean the armature at the 
same time, is to lay the two pieces, channels uppermost, on a 
table, putting a little fine sand and water in the channels, and 
then to work the armature up and down the channels, first in 
one and then in the other, alternating also the sides of the 
armature, until the channels, as well as the external surfaces 
of the armature, are rendered quite smooth and bright. The 
sharp corners of the legs of the magnets around which the 
wire has to be coiled must also be rounded, and the top semi- 
circular flanges, between which the standard has to be clamped, 
must be filed quite flat on their inner surfaces, and made per- 
fectly parallel with the portions marked 3% B, Fig. 14. The 
standard must also be cleaned in like manner, particular care 
being taken that the two sides of the piece marked B, Fig. 
16, be perfectly parallel. The edges of the front piece e must 
be made perfectly square and true, so as to fit exactly on to 
the top of the two legs of the magnets, Fig. 14. 

§ 23. Before winding the armature and field-magnets with 
the wire in which the electricity is at once generated and con- 
ducted, it is necessary to fit together accurately the different 
portions, and mark theni, so as to be able to put them together 
again in precisely the same position after winding; since no 
filing or fitting can be attempted on the castings after the 
wire has been wourid without almost certain destruction of the 
insulation, and certain ruin to the neat appearance of the 
evenly-laid wire. 

The part that calls for the greatest care and attention is the 
armature, which, as it must rotate in very close proximity to the 
poles of the field-magnets at a rate varying from 1,000 to 3,000 
revolutions per minute, requires to be centered most accurately 
on its bearings or trunnions. This to the possessor of a lathe 
presents but little difficulty; for the benefit of those who de- 
pend Oft. ordinary tools only, the following method, by which 
the armature can be mounted on its bearings in a fairly accu- 
rate manner, is described. With a pair of calipers, the diam- 
eters of the two opposite extremities of the armature are taken. 
(If the armature casting were finished up quite exactly, 
these two measurements would be exactly alike, viz., a trifle 
under 1 1^ inches each. But unless turned on the lathe, it is 



FvgAB: 



5^/ 

very rare to get such precision. ) Two circles, of exactly the 
same diameters as the two extremities of the armature, are 
BOW to be struck out of a piece of hard sheet brass, ^ of an 
inch thick, care being taken to mark the center and the cir- 
(^umference in an exact and bold manner with the compasses. 
These circles will have to be cut out of the brass with a saw 
or file, so as to get two discs, fiting each one to its respective 
armature extremity; but before cutting out the circles thus 
marked, three holes should be drilled in each, viz., one in 
the exact center -\- of an inch in diameter, which is to take 
the driving shaft or trunnion, and one on each side of this 
center, ^ of an inch in diameter, to admit the screws which 
serve to attach these heads or discs to the iron portion of the 
armature. Besides these three holes, which are common to 
both "heads," another pair^ also ^ of an inch in diameter, 
must be drilled in one of the heads, to allow the ends of the 
wire which is to be coiled around the armature to emerge 
from them, and pass through to the commutator All these 

holes are shown///// szze, and in 
their correct position at Fig. i8, 
where a is the central aperture, to 
take the shaft; d b the two holes 
to admit the screws, whereby the 
heads are attached to the arma- 
ture ; and c c holes drilled in one 
head only, to admit of the passage 
of wires to the commutator. 
These holes being bored, and the 
discs accurately cut out, two pieces 
of hard-drawn iron wire (not galvanized) ^ of an inch diameter 
and 2 inches long, are carefully straightened, and by means of 
a screw-plate, a thread is put on one end of each. With the 
corresponding tap, a female screw is cut in the central hole 
of each brass disc. The two iron rods are then screwed in, 
particular care being taken that they enter perpendicularly 
and centrally. They must be screwed in until they just pro- 
trude through to the other side; then the long end being 
allowed to slip between the jaws of a vise, while the disc 
rests flat upon the surface of the jaws, a few steady blows 
with a flat-pened hammer will spread the head of the screw 
end of the iron rod, so as to rivet it firmly to the disc, and 
thus prevent it working out. To render assurance doubly 
sure, a drop or two of soft solder may be run round the flat 




5o8 



side of the end of the rod and disc. Now we come to a part 
of the work that very few amateurs can do at home — viz., 
drilUn-g the holes in the faces of the armature. Any black- 
smith will, however, do this for a few cents. Four holes are 
required, two at each end of the armature (one end is showa 
real size at d d), and these holes must be tapped with a 
female screw, so as to take the screws which serve to uni^e 
the whole together. It will be well to let the blacksmith 
drill and tap these holes to any sized screw that he has near- 
est approaching /^ of an inch in diameter. Now will be 
also the time to get the blacksmith to drill the three holes, 
right through the top end of the legs and standard, which 
serve to allow these portions to be clamped together by 

means of bolts and nuts. These 
holes should be about }^ of an 
inch in diameter. Further de- 
tails as to position and size will 
be given a little farther on. If 
our work has been properly per- 
formed, the heads may now be 
screwed down to the armature 
with flat-headed screws, which 
should project about --^ of an 
inch above the level of the disc. 
Fig. 19 gives a representation of 
the finished armature about half 
the real size. 

§ 24. Our next proceeding is 
to clamp together the stand- 
ard, or bracket, which serves to support the wheel to 
the two legs of the field-magnets. At the concluding 
portion of ^ 23, we adverted to the advisibility of getting 
the holes bored right through the top end of the legs 
and standard, at the same time that the holes were 
being drilled in the armature. The position of these holes 
is indicated at Fig. 20; they should 
be about X of an inch in diameter, and 
the two lower ones should be at least ^ 
of an inch from the bend of the flange, 
so as to allow the nuts to be easily turned 
and tightened up. These two bcttorxi 
holes should be about two inches apart, 
while the upper one should st^^nd equi- 
distant from the others, but at about y^ 





5^9 

an inch from the top of the flange. The amateur %vill find at 
^ any hardware store, very neat skate-screws with nuts to fit, 
of the form illustrated at Fig. 21. These screws have usually 
rounded heads, without the slot for the screw-driver to enter; 
but these can be easily cut with a metal saw. Oi course, 
i any small bolts and nuts hav- 

[oj Tc\ ing a section of about X of an 

\ I I I inch will do, but the ones men- 

I I ■ ' I I I tioned are very neat in appear- 

j ^1 (^ I ance. The holes being drilled 

and the bolts and nuts chosen, 
the bracket and limbs of the 
field-magnet may be tempo- 
rarily clamped together, in 
order to see what opening is 
left between the legs for the 
armature to turn in, at a, Fig. 
22. In all probability some 
filing of the faces of the flanges 
and of the bracket will be nec- 
essary to insure a proper fit. 
A well-fitted armature, if placed 
in the center of the channels at 
a, should leave a space of a trifle more than 2^ df 
an inch to turn in; that is to say, there should be ratner 
more than ^o of an inch clear space all round between the 
armature and the field-magnets. Perhaps the quickest 
way to insure this distance being obtained is to roll 
tightly a single fold of stout brown paper round the 
armature and seal down the edge to prevent it slipping; then 
having inserted the armature in the channels, to file away at 
the inner faces of the flanges, either toward the lower por- 
tions at d b, if the channels are too wide apart, or at the 
upper extremities at c c, if too close, until the whole fits 
accurately together.. It is needless to remark that when the 
armature thus wrapped in paper is placed between the field- 
magnets, to obtain a correct fit, the solid portions of the 
armature should lie against the legs, and Tjot the portion of 
the armature which is hollowed but for the reception of the 
wire. (See Fig. 22.') '" 

tj) 25. The magnets and brackets being thus properly 
clamped together, the hole in the top of the bracket (which 
ought to have been left in the casting, but it not maybe 




510 

bored now) should be cleaned out to % an inch in diameter. 
When this is done, two pieces of hard rolled brass sheet Y^ 
of an inch thick, 6 inches long by I inch wide, must be cut 
out and squared up. One of these, which we shall for the 
future call the " back bearing," and which must be made to 
lit that end of the dynamo at which the driving wheel is to 
be placed, and which we shall henceforward call the " back *• 
of the dynamo, is to be bent four times at right angles, as 
shown at Fig. 23, a^ where the dimensions are given. In 



<- 



— jyz inches •••••.••• > 



iSE 









•^••"•••— •»—"-— •"••••■ tf/Jfi •*«**«a«»a»s««*a«.wia (^ 






; 




order not lo crack the brass while bending to shape, it will 
be well, after having given the general form by bending 
gently and gradually over the jaws of a vice, to heat the 
bends over the flame of a spirit-lamp until nearly red hot, 
and then to hammer up more exactly to shape, repeating the 
heating after each hammering until the desired sharpness of 
outline ha^ been obtained. 



When this object has been attained, another almost similar 
bearing is formed out of the remaining piece of sheet brass, 
the principal difference being that, as this is to be the front 
bearing, between which the commutator will have to turn, 
a much greater depth must be given to the central bent 
portion, as may be seen at Fig. 23, b, the dimensions being 
given in inches as before. When the brass has been bent 
to these forms, the bearings thus produced should be laid 
each against its own respective end of the dynamo, in such 
a position that the center of the bend comes in the center 
of the channel, the two flat extensions lying close to, and 
flat agamst, the slotted lugs shown at Fig. 22, d d. The 
bearings should now be cut m a sloping fashion to follow the 
outline of the lugs, as shown at Fig. 23, c ; but the outline 
of the slotted portion should not be followed, as a ^-i^^h 
hole must be drilled in the brass at this point to take a 
5-inch bolt and nut. Tlie exact position of these holes may 
be obtained by holding each bearing in succession against its 
own proper extremity, and scratching with a steel point on 
to the brass the position in which the slots in the lugs fall ; 
'.hen, with a Morse twist drill, a ^-inch hole can be drilled 
at each extremity nearest to the center of the bearing, as 
shown at Fig. 23, d. 

Having got so far, let us clamp the back bearing in its 
place by means of two bolts about 5 inches long, passing 
through the holes in the bearings and through the slots in 
the lugs, held in their places by two nuts screwed down on 
to the front lugs of the dynamo. Taking the armature in 
one hand, we roll, as before, one fold of paper round it, and 
put a dot of Brunswick black on the extremity of the trun- 
nion rod at the back end of the armature (the end where the 
holes are bored for the wire to come out is the front, the 
other is the back), and then insert it into the channel 
between the legs of the field-magnets, until the trunnion rod 
on shaft touches the brass forming the back bearing. In so 
doing it will leave a mark of Brunswick black, which will be 
the point at which a %-\x\Q:\i hole must be bored. This 
must be done most carefully, so as to preserve centricity ; 
and when done must be rimed out and bushed with a piece 
of brass tubing of about -^(r external diameter, the internal 
diameter of which must exactly correspond with the external 
diameter of the driving-shaft or trunnion of the armature ; in 
fact, this latter must fit exactly into the tube, without anv 



5T2 

shake. This piece of tubing should be about iX inches in 
length, and should be soldered into the central hole in the 
back bearing, and should extend inward to such a degree 
that when the back bearing is clamped in its place, with the 
armature in its position, with the back trunnion in the tube, 
and the back head flush with the back of the magnets, it 
should just rest against the back head of the armature. 




In a precisely similar manner the center of the front 
bearing is found ; that is to say, the back bearing being 
removed, the front bearing is clamped to the front of the 
dynamo, the armature, rolled in one fold of paper, is inserted 
from the back end of the dynamo, front end forward, and 
care taken to moisten the front end of the driving-shaft with 
Brunswick black or other color, so as to get a mark where 
it touches. The hole being drilled and rimed out, as in the 
previous case, is to be likewise bushed vdth the same kind of 



513 

brass tubing ; but in the front bearing, the tube should be 
only flush with the inside of the bearing, and skottld not 
extend in toward the armature, 

% 26, The Com77iutator w^yX claims our care. This essen- 
tial piece of apparatus serves, as the student may remember 
(§ 12), to rectify, or send in one direction, the vibrations or 
currents which are produced in opposite directions, as each 
pole of the armature passes alternately before the north and 
south pole of the field-magnets. In screwing the brass heads 
down to the armature, the student was advised (§ 23, Fig. 19) 
to employ flat-headed screws, projecting about | of an inch 
above the level of the discs. The use of the projecting 
heads is to prevent the commutator slipping round the axis 
or trunnion of the armature when the latter revolves. The 
body of the commutator may be turned up out of a piece of 
sound boxwood, which previous to turning up should have 
been allowed to soak for a couple of hours in melted paraffine. 
It should, when finished, present the appearance shown at 
Fig. 24, a. While on the lathe, a hole, perfectly central, 
should be drifted right through it, into which the front shaft 
or trunnion of the armature fits tightly. The length of this 
should be §2 of an inch, so that it just clears the front bearing 
when in its place. The diameter should be about \ of an 
inch, so that the two flat-headed screws of the front arma- 
ture head should be covered by the cyHnder on opposite 
sides of its circumference to the extent of about ^ of an inch. 
Tvvo semicircular nicks must be cut out of the bottom of the 
cylinder to allow these screw heads to enter, so that the 
cylinder when driven home rests quite against the disc or 
head. The front of this cylinder (the part farthest from the 
disc) must be rounded slightly, so as not to present too great 
a surface for friction against the front bearing. A piece 01 
brass tube, y% of an inch shorter than the cylinder, and of such 
internal diameter as to fit tightly on it, is now cleaned up and 
cut into two exactly equal halves longitudinally. The cuts 
must not be quite parallel to the axis of the cylinder, but 
must make a small angle with it, in order that the " brush " 
or spring which takes the current off the commutator should 
at no time abruptly leave one half tube before it rests on the 
other; otherwise the commutator sparks badly while at work, 
and the sparks injure both commutator and brushes, besides 
entailing loss of current. The amount of angular deviation 
from the line of axis should not, in this machine, exceed two 



5H 

or three degrees of arc, and care must be taken they are 
equi -distant, and both inclmed in the same direction. To 
insure this, stand the tube (already cut to length and cleaned) 
on one end. Take the exact diameter with a pair of com- 
passes, and strike out on a piece of card a circle of exactly 
similar diameter. Rule two fine lines across this circle, both 
cutting the center, but exactly ^ of an inch apart at the cir- 
cumference, like a letter X. Lay this card on the top of a 
tube, and with a steel point or file make a mark on the rim 
of the tube at each of the points where the lines touch the 
circumference of the circle. Now lay the tube on its side, 
and draw four lines straight along the length of the tube, 
starting from the points just marked. Fach opposite pair ol 
lines will be exactly ^ of an inch apart, and quite parallel. 
Having done this, bring one pair of lines uppermost, and 
draw a diagonal line from the top of the right hand to the 
bottom of the left-hand line. Now turn the tube half a rev- 
olution, so as to bring the lower pair of lines uppermost, and 
draw a similar diagonal line, in the same direction — viz., 
from the top of the right hand line to the bottom of the left- 
hand line. Now, with a fine fretsaw cut the tube into two 
halves in the direction of the two diagonal lines just de- 
scribed. The tube, with the diagonal lines marked ready for 
cutting, is shown, as if transparent, at Fig. 24, b. It will be 
noticed that though, when seen through, these lines cross 
each other, yet when either portion of the marked tube is 
uppermost the line of division is from right downward to 
left. The split tube is now to be fastened to the boxwood 

cylinder in such a position 
that the middles of the lines 
JFi/Cf • -J J" Z/^*^^ °^ division shall be exactly 
•^ * / / J^ in a line with the middle of 

the channel of the armature. 
(See Fig. 25.) These two 
half-tubes may be attached 
to the boxwood cylinder or 
core by means of two short 
flat -headed screws, care be- 
ing taken that these screws 
do not reach to make con- 
tact with the trunnion or 
touch the "head" of the 
armature. The split ring. 




5^5 

when fastened in its place, should reach to within about }i 
of an inch of each end of the boxwood core; and if screws 
are used to fasten it down these should be placed at the end 
nearer the armature. But another \ery neat and effective 
way of attaching the split tube or ring to the core is by means 
of two narrow ivory or bone rings, forced over the split tube, 
one at each end. Care must be taken, in either case, that 
the divisions in the split tube are maintained; for, of course, 
if the two halves of the tube were allowed to touch at any 
point the current would flow round at that point or " short 
circuit," and no current would be perceptible on the outside. 
To insure the distance being maintained, it is well to place a 
shaving of paraffined wood of the same thickness as the saw- 
cuts between the two halves of the split tube on both sides. 

^ 27. Those who have not a lathe can make a very fair 
substitute for the boxwood cylinder by rolling and gluing a 
stout piece of brown paper, just as if making a rocket-case, 
around a piece of the same iron rod that served for the trun- 
nions of the armature, until a cylinder J4 of an inch thick 
and U of an inch long has been produced. This should be 
rolled very hard while on the iron rod, so as to insure 
its being truly cylindrical; the rod on which it was rolled 
should then be pulled out, and the tube allowed to dry thor- 
oughly. When dry it should be soaked for half an hour in 
melted paraffine. then reared on end to drain and cool. It 
will be found to work extremely well. Of course the split 
ring can be attached to this, either by screws or by two rings, 
as in the former case. 

§ 28. Tw^o rectangular pieces of boxwood (previously 
boiled in paraflfine) must now be cut, planed and drilled. 
These are the " brush blocks," which serve to support the 
metallic^springs or " brushes " which press against the com- 
mutator. Some operators prefer to mount their blocks on 
the stand, separate from the dynamo castings; nere che plan 
followed is to cause the bolts which clamp the bearings to 
the field-magnets to carry the brush blocks. To this end the 
two pieces of boxwood should be cut so as to fit exactly the 
space left between the shoulders of the front bearings 
o/i the outside^ and bored so as to allow the bolts to come 
right through to take the nuts; that is to say, the blocks will 
be almost cubicalin shape, being i inch long, |^ of an inch 
wide, by % of an inch thick. Fig. 26 shows one of these 
blocks in its place, clamped to the bearing by the nut and bolt- 



5^0 

§ 29. In order to communicate the motion from the fly, 
Wrheel to the armature, a small pulley-wheel, either of iron 
or brass, is fitted to the back trunnion, just outside the 
bearing. Such a pulley- wheel may be bought at any hard- 



jFCj^ . it) 




■f-^ 




^ 



/V^27^ 



ware store, and should be about i^ inches in diameter, and 
rather over ]^ of an inch thick, with the central hole some* 
what smaller than the diameter of the rod which serves foi 
the armature trunnion. This 
may be attached to the trunnioii 
in either of the two following 
ways: ist. By " keying, "which 
consists in filing the trunnion 
along its length in one direction 
only, so as to produce a flattened 
side ; then, having with a rat- 
tail file cleaned out the central 
hole of the pulley to such an ex- 
tent that the said trunnion will 
only just enter, to deepen one 
side (corresponding to the 
flattened side of the trunnion) so 
as to admit of a small steel 
wedge or " key " being inserted. 
(See Fig. 27, a.) 2nd. By filing 
the trunnion-rod to a slightly 
conical shape, and producing a 
similar " coning '' in the interior 
of the pulley hole, which may 



then be driven on. (See Fig. 



27, ^, where the " coning "of the 
trunnion is exaggerated, to 
render this mode of attachment 
more plainly visible.) Which- 




^ — Sfi -- 



SJ7 

ever mode of attachment is adopted, one precaution must b^ 
taken — viz., that the distance between the back of the 
field-magnets and the pulley should not be less than i^ 
inches; otherwise, when the limbs of magnets are wound wit'j 
wire, the fly-wheel will run too close to them to be altogethei 
safe. 

§ 30. The fly-wheel which gives motion to the armature 
should be a pretty heavy wheel, about 13 inches in diameter, 
with a groove in the rim to take the band which drives the 
pulley, furnished with a wooden handle for convenience of 
rotating. Such wheels may be obtamed ready made in cast- 
iron, from most hardware or agricultural implement dealers, 
as they are sent out with "rotary blowers," "portable 
forges," etc. Fig. 28 a gives an idea of the kind of wheel 
necessary, on a scale of ij^ inches to the foot. The central 
hole is turned, and only requires fittting with an 
iron pin, on which it turns. Since the aperture 
in these wheels is about 3^ of an inch in diam- 
eter, the pin must be filed down to ^ an inch diameter, 
where it h^s to fit the hole in the flange at the top of the 
dynamo. 

The farthest end should have a rounded head, to prevent 
the wheel from working off, wnile the portion which passes 
into the eye at the top of the flange must have a thread put 
on it, so as to take a nut. (See Fig. 28, b.) 

§ 31. All the portions of the dynamo being now fitted, they 
should be marked so as to insure putting together again in right 
order after winding. When this has been done; the limbs of 
the field-magnets, at all parts except the channel for the arma- 
ture, and the inner face of the semicircular top which rests 
against the wheel bracket, should receive a coat of good 
Brunswick-black, allowing them to dry between each applica- 
tion, in a warm oven. The bracket should likewise receive 
a coat or two of the same varnish, exce]:)t where semicircular 
tops clinch it. This portion viust be left metallic, so as to 
insure magnetic contact; otherwise much magnetic power is 
lost. Two strips of silk (color immaterial) 10 inches long by 
3^ inches wide, should now be quickly brushed over with 
Brunswick-black, and wrapped, while still sticky, one round 
the one limb, and the other round the other limb of the field- 
magnets, in the space between the armature channel and the 
bend at the top. (See Fig. 14, where the portions indicated 
are marked respectively 4" and 3X"-) '^^^^ object of this silk 



5i8 

wrapping is to insulate the wire thoroughly from the iron, 
and to prevent any accidental abrasion of the covering wire, 
which may take place during careless winding from short en-- 
cuiting to the iron below. When the silk has been laid 
smoothly and tightly on, the limbs may be returned to the 
oven, and allowed to dry at a gentle heat. In precisely the 
same manner the interior faces and their central portion of 
the armature (technically known as the " web ") must be var- 
nished with Brunswick-black, and wrapped with one layer of 
similarly prepared silk. Three pieces will be required to do 
this effectually — viz., two pieces 3^ inches long by 1% 
inches wide, shaped as in Fig. 29, to fit against the 
inner faces, and one piece 6 inches long, by %. of an inch 
wide, to wrap round the web. Particular care must be 
taken that every portion of the inside of the armature's 
channel be entirely covered in silk. When this has been 
satisfactorily performed, another coat of Brunswick-black may 
be given (avoiding to soil the outside), and the armature 
allowed to dry thoroughly in a warm oven. 

§ 32. Our dynamo is now ready fcr wiring. For this pur- 
pose we shall require about 7 lb. of No. 16 single cotton- 
covered copper wire for the iield-magnets, and about ^ lb. 
No. 20 double silk-covered for the armature. The amateur 
should be careful to get 7iew wire, of the highest conductivity, 
and very soft; the employment of old, kinky, and hard wire 
is fatal to success. 

§ 33. The quantity of wire above mentioned having been 
duly selected, it should be tested for continuity. The No. 
16 will give evidence to the sight alone, whether there be 
any break in it or not. Should there be such, the covering 
from the two broken ends should be uncovered for about an 
inch on each end, the two extremities filed down to a fine 
flat wedge, so as to fit one another, when each one separately 
should be warmed for a second over the flame of a spirit- 
lamp, dipped into powdered resin, and rubbed, while being 
held in the flame of the lamp, with a rod of solder, until 
each has taken a good coating of solder. The two ends may 
then be applied with their flattened portions together over 
the flame of the spirit-lamp until the solder coating melts. 
Keeping the ends pressed together, the wire is to be removed 
from the flame. The solder coon hardens, and the wires will 
be found firmly united. It is now only neces^sary to file 
away any roughness, and rewind the cotton covermg over the 



519 

bared portion, adding a little darning-cotton if the covering 
be deficient. The finer wire, which is generally bought on 
reels, had better be tested with the galvanometer (Firf. 2). 
To this end, find the two extremities of the wire, attach one 
to one binding-screw of the galvanometer, the other extrem- 
ity being in good metallic contact with the pole of any single- 
cell battery. Connect the other pole of the battery with the 
other binding-screw of the galvanometer. An immediate 
and large deflection of the needle will show that the wire is 
continuous. If not, the wire must be unwound from the 
reel, and carefully wound on to another until the point at 
which the break occurs has been discovered. The two broken 
ends maybe joined as described above, great care being taken 
after joining to recover the point of junction thoroughly, so 
as to preclude all danger of leakage, more silk being used to 
this end if necessary. It having been ascertained that the 
wire is perfect and in good condition, the next step is to soak 
it in melted paraffine wax, The good effect of this is twofold*. 
(a) The ii:sulation is thereby rendered very much better; 
{d) a damp atmosphere has then little or no effect on the in- 
sulation, since the paraffined cotton and silk covering is no 
longer hygroscopic, and may actually be pumped upon with- 
out becoming wetted or spoiling the insulation. To parafifine 
nicely the wire should be laid in a shallow dish large enough 
to contain it easily — a circular tin baking dish will do admir- 
ably. It should then be placed in a warm oven, not too hot, 
until it is about the heat of the hand — say, 90^ Fahr. About 
}4 lb. of good parafiine wax should now be placed in the 
tin, and the oven closed until the paraffine is all melted. The 
wire may then be turned over two or three times until it is 
seen to be thoroughly soaked with the paraffine. Two or 
three metal rods should now be placed across the top of 
the dish, on which the wire may be placed to drain for a few 
seconds while still in the oven. When it ceases to drip it 
tnay be removed from the oven and allowed to cool. The 
superfluous paraffine, while still hot, may be poured into 
a cup (whica has been just previously breathed into) to 
set, when it may be used for other insulations. 

2 34.. ^vinding tiie armature next clains our attention. 
Having marked t 1 t h"ads,soasto know which belongs to 
a given extremityc )[ the armature, we unscrew and remove 
them; about 6 iiiciit^sof the extremity of the No. 20 wire 
should be coiled tightly round the end of a pencil, so as to 



S20 



form a tight helix from which the pencil must then be slipped 
out. This helix will form one of the spare ends of the wire 
which, will be attached to the commutator, and should be, for 
the time being, tied with a bit of silk to the outside of the 
armature, so as to be out of the way while winding. Hold- 
ing the armature in the left hand, with the end which corre- 
sponds to the commutator facing us, and beginning at the left- 
hand cheek, we wind the wire in the channel, continuing to 
wind until we reach the right-hand cheek, taking care to lay the 
wire on as closely as possible, never allowing it to ride over 
its neighbor, nor yet to leave gaps between. When one 
layer has thus been carefully wound on, as shown at Fig. 30, 
it should be tested for insulation, since 
the amateur is very apt to wind care- 
lessly and cut the insulating covering, 
either by catching in the sharp corners 
of the channel or otherwise. To test 
for insulation, tie the end of the wire 
(without detaching it from the reel or 
hank) against one cheek of the arma- 
ture, to prevent its unwinding during 
the trial; then connect one pole of a 
battery to one binding-screw of a gal- 
vanometer, and the helix end of the 
wound wire to the other binding-screw. 
On touching the iron of the armature at 
any point with the other pole of the bat- 
tery, no deflection of ^he needle should 
take place. Should a deflection show itself, evincing a 
metallic contact and want of insulation at some point, the 
wire must be unwound, the flaw localized and remedied 
by a fresh covering of silk, basted with 23araffine, and again 
vvcimd on and tested until the insulation is satisfactory. A 
layer of thin paraffined paper should now be laid over the 
first layer of wire; and the winding proceeded with in exactly 
similar manner, until the second layer has been laid on, 
remembering that the essentials of success are to wind the 
wire as closely as possible in each laver without overlapping; 
to avoid grazing the covering of the wire, so as to maintain 
insulation, and to wind always in one direction — viz., from 
tis, over to tinder. There is no necessity (when using silk- 
covered wire) to place a stratum of paraffined paper between 
each layer of wire, as this, by incfeasing the distance between 




521 

tne layers, soraewhat decreases the efficiency of the machine; 
this is only advisable when the insulation of the wire has been 
found to be imperfect. The winding should be proceeded 
with, layer after layer, evenly, tightly and smoothly, until the 
wire just fills the channel. Care must be taken that it does 
not exceed this, for if it comes higher than the cheeks it will 
surely catch in the limbs of the field-magnets during rotation. 
From eight to nine layers of wire may be laid on, according 
to the tightness with which it is pulled during winding. 
When the due proportion of wire has been laid on, it should 
be fastened down by tying, so as not to unwind, with its free 
end at the same extremity (the commutator end) as we 
started from. The helix may now be straightened out, and 
its condition observed, to insure that it is well insulated. 
The end at which we finished winding should also be 
straightened out and examined for good covering "T^hen 
a stick of elastic glue should be heated and ribbed 
over the covered ends right up to the armature, so 
as to thicken them to such an extent that they will 
only just pass through the holes bored in the head to which 
the commutator is attached. (See Fig. i8, r, c.l The 
wire ends should be passed one through each of these Iioles 
(care being taken that the head be put on as it was previous 
to removal), pulled pretty tightly, but not so roughly as to 
graze or injure the covering, and having been cut so as to just 
reach the heads of the screws, which fasten the two halves 
of the split tube of the commutator to its cylinder (see Fig. 
25), should have their extreme ends unwound and cleaned, 
and then be soldered down, one to each half of the split 
tube, care being taken that neither the solder nor the wire 
passes beyond the line of the screws; so as to leave plenty 
of room for the brushes to press against the commutator. 
The heads may now be screw^ed up in their place, and a 
coat of good sealing- v^ax varnish (best made by dissolv- 
ing good scarlet sealing-wax in methylai ed spirit) painted 
over the layers of wire, both for the sake of appearance 
and to keep the wires from moving out of place during 
rotation, though if the wires are tightly wound this would 
be hardly needful. This coat of varnish must be allowed 
to dry off in a warm atmosphere (not in the oven), and 
the armature will be complete. 

i 35 Our labors are now drawing to a close. To wind 
the Seld-magnets it will be as well to rig up a little piece of 



apparatus, since, although they may be wound without, it 
is very difficult to lay the wire as closely, as tightly, 
and as neatly as can be done by its aid; and since the effi- 
ciency of the machine is greatly exalted by the greater proxim- 
ity of the wire to the core, it is a matter of considerable 
importance that this should be attended to. The apparatus 
necessary consists of a handle fastened to an axle passing 
through a standard supported on a base; the axle having a 
prolongation to which each limb of the field-magnets can be 
screwed down in its turn. On turning the handle, it is evi- 
dent that the iron mass of the field-magnet will rotate on its 
axis, and i^^are be taken that the center of the mass coincides 
with the center of motion, the motion imparted to the iron 
will be smooth and even, and the wire may be laid on with 
great exactitude and closeness. This apparatus is illustrated 
at Fig. 31, a, with one of the limbs of 
the field-magnets screwed in its place, 
ready for winding. It should be made 
out of ^-inch stuff, the base being 
about 5 inches wide by 6 inches long. 
The upright through which the axle 
passes should also be about the same 
size, and screwed to the edge of the 
baseboard, so as to stand at right an- 
gles to it. A short piece of broomstick, 
about % of an inch in diameter, may 
be used as the axle, and a hole must be bored in the upright, 
at about 4 inches from this base, to admit this axle. To the 
external portion of the axle is fastened a handle; while to the 
internal portion, which should protude about i^ inches, is 
screwed a piece of ^^-inch stuff about ij^ inches square, half 
the axle being cut away to admit of its lying fiat. Previous 
to screwing down, the handle, as well as 
this latter square piece, should be 
rubbed over with a little good hot glue 
at the places where they touch the axle, 
to insure a good sound joint. This 
" winder " being completed, it may be 
clamped to a bench or table by means 
of a sewing-machine or fretsaw clamp, 
the leg of the field-magnet having been 
previously screwed to it by means of the 
three holes in the flange, in the position 
shown in the figure. Though shown in 





^^ 



'>23 

the cut to the left^ the handle of the winder should be to the 
right of the operator, unless he be left-handed. In commenc- 
ing to wind the wire, the operator should stand over his 
work, a sheet of paper having been placed on the floor, and 
the coil of paraffined wire at his feet, with a two-gallon stone 
bottle filled with water, to keep the bottle from upsetting, in 
the center of the coil to prevent its tangling or kinking. The 
surface of this jar being glazed, the wire slips from it without 
injuring the covering. The winding should be commenced at 
the extremity farthest from the handle — that is, nearest to 
the channel in the field-magnets in which the armature ro- 
tates. Six or eight inches of the wire should be coiled round 
a pencil, and so as to form a tight helix, which, with a piece 
of strong twine, should be tied to the leg of the magnet, as 
shown in Fig. 31, b. Holding the loose end of the wire 
in the left hand, keeping it pretty tightly pulled, and 
straightening it out from its coiled shape as it passes through 
the fingers, it is easy in this manner to wind the wire per- 
fectly flat and smooth by turning the handle of the winder in 
the direction of the motion of the hands of a watch. (In or- 
der to prevent any accidental contact though abrasion against 
the corners, etc, it is advisable previously to cover the legs 
of the field-magnets, at all events as far as the wire is to ex- 
tend — viz., from do d'vcv the present figure — with a band of 
silk dipped in melted paraffine, and applied hot to the iron, 
when it will immediately adhere. This band must be care- 
fully smoothed down, so as not to cause unevenness in the 
winding of the wire.) If the wire be nicely laid on, it will 
be found possible to wind forty rows between c and d. Be- 
fore arriving at d it will be necessary to place two pieces of 
tape about ^ an inch wide and 3 inches long, as shown 
at ^ ^ in the figure, the free ends of which must be turned 
back smoothly and tightly over the layer just put on when d 
is reached. Continuing the rotation of the handle in the 
same direction, another layer of wire is now laid over 
the first; by holding the ends of the tape fast while 
beginning to wind this second layer, all tendency of sinking 
into the layer beneath, which may be displayed by the 
second layer, is overcome. Without this precaution it is 
almost impossible to prevent the outer layers of wire sinking 
into the interspaces of the layers below. Continuing in this 
manner, layer after layer should be laid on until seven layers 
have been wound, remembering to use tapes toward the end 



524 

of each layer, and that each layer will diminish by two^rows. 
When the seven layers have been laid on, the wu-e must be 
tied down to the magnet to prevent uncoiling, and cut c 7 
from the hank of w^ire, leaving about 6 inches free for attach- 
ment. 

In exactly a similar manner as regards attachment, direc- 
tion of winding, etc. , must the second limb be wound. The 
only difference that need be made is that, for convenience of 
having both ends of wire at the same end of the dynamo, it 
will be w^ell to fasten the beginning of the wire (the helix) to 
the inside of the leg instead of to the outside. Fig. 31, f, 
will make this clear. 

% 36. Both for the sake of appearance and to further pro- 
tect the insulation from damp air, etc. , it is advisable to give 
the wires on the limbs of the field-magnets a coat of 
good varnish. The best for this purpose is made by mix- 
ing about 2 ounces of the best red lead with ^ an ounce 
of good white hard varnish. The two should be v/ell incor- 
porated together by working with the brush intended to be 
used for laying on the varnish. 

The varnish should be applied in a thin layer with a soft 
brush, so as to disturb the paraffine coating as little as possible, 
since if the paraffine mixes with the varnish, this latter never 
dries, but remains a sticky mess. For this reason the coating 
of varnish should be allowed to dry without the application 
of heat, which, if the " white hard " be good, it will do in 
about eight to twelve hours. A second coat may be given if 
desired; but as this generally fills up the interstices between 
the layers of wire, it detracts somewhat from the neatness of 
the appearance. 

§ 37. The varnish being quite dry^ the dynamo may again 
be put together, care being taken that the parts are ad- 
justed in the position which they occupied after fitting. If 
this has been properly done, the armature ought to turn 
freely in its bearings quite close to the limbs of the field-mag-^ 
nets, but without catching anywhere. 

Supposing this to be all right (and it must be so, or the 
dynamo cannot work properly), the dynamo must be screwed 
down to a baseboard, v/hich should consist of a slab of oak, 
walnut, or m.ahogany, 10 inches long by 8 inches wide, and 
at least i inch thick. The two lioles in the lower flange in 
the limb of the field- magnets, near the channel in which the 
armature revolves, are expressly for the Durpose of clamiping 



525 

the dynamo to its baseboard. The baseboard should be 
chosen of a well-seasoned nature— polished, for appearance 
sake; and the dynamo should be screwed to it centrally, with 
the narrowest portion of the dynamo parallel with the narrow- 
est portion of the baseboard. 

Attachment of the Wires. 

§ 38. The dynamo having been wound as described (and 
care must be taken to have fulfilled the instructions exactly, 

or else the resulting magnet will 
have two /^^r//^ poles, or t wo j-^//^^ 
poles, instead of one north and 
one south), we can proceed to 
couple up the various parts. To 
this end we begin by joinmg the 
wires at the two extremities at 
which we left off winding. This 
may be effected by removing a 
portion of the covering of the 
wires (by scraping with a sharp 
knife) for about an inch along the 
places where the two wires cross 
each other if made to touch. (See 
Fig. 32^.) 

The wire must be made quite 
bright and clean by rubbing with a bit of sandpaper at this 
point, and then the wires are twisted tightly together by the 
aid of a pair of pincers. A drop of solder, taken up on a hot 
soldering-iron and run along the twisted portion will insure 
the contact remaining good. The excess of wire should now 
be cut off from the twisted end with a pair of cutting pliers; 
the bared twist bound round with a layer of darning-cotton^ 
varnished with the red varnish (§ 36), and turned in out of the 
way between the limbs of the magnet. (P'ig. 32, b.) 

We may nowproceed to magnetize the field-magnets. For 
this purpose we need only attach the poles of a single-cell bichro- 
mate battery, exposing from 8 to 10 square inches of negative 
surface, to the wires of the dynamo for a few seconds; but in or- 
der to obtain results which may be deducible from reason, and 
which can be corrected if mistakes are made, it is desirable to 
determine beforehand which shall be the north pole of our 
future magnet. It will be remembered {% 8) that we have it 
in our power to prcduce a north pole, to onr Icft^ in t. mass 




526 

of iron, by passing a current of electricity away from us, 
over it; and if we wish to produce 2 north pole to the right^ 
the current must come toward us, over the mass. 

Let us decide to make a north pole of the limb on which 
we began to wind the wire on the outside. (See Fig. 31, r.) 
To do this the current ought evidently to flow from the 
limb of the magnet to the observer; in other words, this wire 
must be attached to the negative pole of the cell. (The 
negative pole of the bichromate cell is the wire proceeding 
from the zinc, the one attached to the graphite being posi- 
tive.) The positive pole of the ce^l must be coupled to the 
other wire, that is, the one which was started from the 
iitside in winding. (See Fig. 31, /!) 

While the battery is thus coupled up to the dynamo, we 
can test if we have produced the effect desired by bring- 
ing a suspended magnetized needle near the supposed north 
pole of the dynamo. If all has been properly performed, it 
will be found to attract the south pole of the poised needle, 
and repel its north pole, 

A few seconds' connection with the battery will impart 
as much magnetism to the field-magnet as it will retain; but 
that httle will be suffici'^^nt for our purpose. Our next step 
IS to discover in which direction the current flows in our 
armature, when we rotate the fly-wheel in the usual way 
with the right hand (in the direction of the motion of the 
hands of a clock). Before we can do this we must fasten 
two " brushes" or collectors on the brush-blocks, in order to 
collect the electricity generated by the rf^volution of the 
armature. 

The Brushes. 

§.39. These consist of two pieces of springy sheet brass, 
y2 of an inch thick, 3^4 inches long, and about }i of an inch 
wide. They must be bent twice at right angles, so as to fit 
tightly on to the brush-blocks ($ 28, Fig. 26), and shghtly 
curved inward at the longer portions so as to press 
with some force against the commutator. (See Fig. 
32, c.) To fasten these on to the blocks, a lateral slot is cut 
about half-way into each brush, at about Y^ of an 
inch from the longest portion, of such a width as to 
admit the shank of a small screw passing into it. The por 
tion of the brush which rests against the armature should be 
slit into two or three divisions, and curved slightly upward 
to avoid scratching the armature. 




5^7 

These^wo brushes, though alike in shape, must be put in 
opposite positions on the dynamo ; that is to say, the one 
which goes on the block to the right of the observer has the 
longer portion above the block, while the one which goes on 
the left-hand block has the longer portion below the block. 
Thus the commutator is rubbed by these two brushes 
at diametrically opposite points. Care must be taken that 
the two screws which serve to fasten the brushes to the blocks 
do not touch the metal of the bolts which clamp the bear- 
ings to the dynamo, for if they did the current would short- 
circuit, and the machine would not work. It will also be nec- 
essary to observe that sufficient curvature be given to the 
longer portion of the brushes to clear the bearings alto- 
gether, otherwise, of course, the 
current would pass into the bear- 
ings and be short-circuited. Fig. 
33 shows the brushes in. their 
proper position ; a^ a being the 
commutator (exaggerated in size 
omewhat to show its position). 
3, b the brush-blocks, r, c the 
brushes, and d, d the screws which, by being tightened or 
loosened, can increase or decrease the pressure of the springs on 
the commutator, and to which the two wires which form the 
electrodes of the commutator are to be attached. These two 
wires, which in our machine may be about 3 inches long, with 
a loop at each end, as shown at Fig. 34 ^, should be of No. 
16 cotton-covered copper wire, the covering beir.g removed 
from the two loops, which must be made 

quite bright. Before putting in the screws ^ 

<'/, d^ Fig. 33, each one should be passed o 1 iv/» 

into one eye of one of the said wires, then '^ 

screwed partly into the brush-block, when the brush itself 
may be pushed into its place over the block, and under the 
screw, the slot in the side admitting of this; 
lastly, the screw is tightened up until the desired 
pressure on the commutator is obtained. 

Fig. 34 shows the position of the wire, screw, 
and left-hand brush on the left-hand block. The 
two free ends of the wires just described project 
straight forward to the front of the machine; 
they may be screwed down on the baseboard, 
at the distance of about 3 inches apart, by means 




5^8 

of a small pair of binding-screws ; the loi<g screws oi which 
are passed through the free eyes. 

We can now test the direction of the cm rent in our arma- 
ture. To do this we place the fly-wheel on its bracket, put 
a leather band (such as is used for treadle sewing-machines) 
round the fly-wheel and driving pulley, then by means of 
two thin wires, which we will screw into the hous of the 
binding-screws just arranged, we couple up the brushes to 
our galvanometer («J 3), and rotate the handle of the fly- 
wheel gently, in the direction we intend to work the machine 
for the future. 

A deflection of the north pole of the needle, either to right 
or left, shows us in which direction the current is traveling ; 
we carefully note, and mark with a paper label, which is the 
binding-screw which is sending the positive current (which if 
coupled to the wire over the needle, causes the north pole to 
turn to the left), since this is the binding-screw which must 
substitute the positive pole of the battery, and to which we 
must attach the wire which comes from the S limb of our 
dynamo. 

§ 40. Two binding-screws are now to be inserted into the 
baseboard, to which the wires proceeding 
from the limbs of the field-magnet must be 
clamped. These should be placed about 
i^ inches from he side of each limb, the 
wires proceeding therefrom being denuded 
of their covering and sandpapered at the 
extremities where they are clamped to the 
binding- screws. These binding-screws (as 
also those connected with the brushes) 
should, for the convenience of being able to 
couple up at one and the same time two or 
more wires, be of the pattern shown at Fig. 
35, in which case the extremities of the 
field-magnets may be also formed into rings, 
as show^n at Fig. 34^;, and either clamped 
down to the baseboard by passing the long 
screw c (Fig. 34) into the ring, or the nut 
a having been removed for the time being, 
the ring may be slipped over the screw b^ 
'■i and then clamped by the nut a. 

Connection is now to be made between the binding-screw 
attached to the current-sending or positive brush (the one 




-^ 



Fvg Sd 



Q/ 



which we have marked with a paper label), and the binding- 
screw coupled to the wire, starting from the inside of the 
limb of the field-magnet (see P'ig. 31, ^) by means of a short 
length of No. 16 copper wire, well cleaned, bent into rings at 
the ends, and clamped down as advised above. 

If all the instructions have been carefully carried out, 
more especially those contained in the last six paragraphs, 
we shall find that on rotating the flywheel a powerful current 
will flow between the two remaining binding-screws — viz., 
the one connected with the outside wire of the field-magnets, 
and the other with the negative brush of the commutator-— a, 
current which will be sufficient to heat to bright reaness 434 
inches to 5 inches of No. 42 platinum wire, or to light lour 
5-candle power lamps, arranged in parallel arc. 

The current actually flowing 
through the circuit (the number of 
amperes) will naturally depend 
largely on the resistance interposed 
between the poles — that is to say, 
between the binding-screws con- 
/0 -f-^ nected with the outside wire of the 

t^^\>, ^/ / field-magnet, arjd the negative brush 

of the commutators respectively; 
and since the magnetism of the 
field-magnet depends entirely on the 
amount of current flowing around 
it, and this again influences the cur- 
rent set up in the armature, it is 
evident that every variation in the 
resistance or the interpolar or out- 
side circuit will produce a corres- 
ponding variation in the current, if 
the dynamo be connected up as 
above described; and that a very 
much larger current will traverse the 
circuit when the resistance is small than when the resistance 
is great. When the machine is doing its best work — that is 
to say, when the resistance of the interpolar is equal to the 
internal resistance of the machine — the current is equal to 
that of eight or ten Bunsen's cells against an equal resist- 
ance. Sometimes it is necessary to send the current through 
a greater resistance; in this case, in order not to weaken too 
greatly the magnetism of the field-magnet by diminishing so 



^ 






& 




530 

greatly the current, it is necessary to shunt off a portion of 
the current, and send it round the limbs of the field-magnet 
by another circuit, which diminishes the total resistance. 

To render this clearer, let us suppose that we wish to light 
up four five-candle lamps, having each an approximate resist- 
ance of eight ohms, and requiring a current of about one 
ampere each to cause them to give out their proper light. If 
we arrange them m series, as in Fig. 36, a, when the total re- 
sistance IS the sum of their separate resistances = thirty-two 
ohms, then, as the electromotive force of our machine when 
at best IS about ten \olts, so i| represents the gurrent flow- 
ing through the lamps, supposing even that the dynamo lost 
no power by the diminution of current (which it does to a 
very great e\cent), and this current is not sufficient to light 
the lamps. But if we arrange the lamps in parallel arc, as at 
Fig. 36, /^ then the total resistance falls to a quarter of one 
single lamp— that is to say; it is 
equal to two ohms only; hence the 
currrent now flowing becomes 
^§ = 5 amperes, and this divided 
among the four lamps gives \}{ 
amperes each, which is ample. 

Again, we find that coupling up 
one single lamp to the dynamo 
presents too great a resistance, so 
that no Ught is given off, since not 
sufficient current can pass round 
the field-magnets to give an elec- 
tromotive force of ten volts. But 
if we insert a " shunt," consisting 
of about a dozen inches of No. 30 
iron wire between the two binding- 
screws aforesaid, as shown at Fig. 
37, and then connect the lamp also 
to the said screws or terminals, 
more current circulates round the 
field-magnets, since two roads are 
now open to the current, the field- 
magnet becomes more powerfully 
magnetic, and in its turn induces 
a much more powerful current in 
the armature, and so on until 
current enough is produced to 





531 

light up the lamp. The resistance of the "shunt" to be 
inserted between the terminals, to produce the best result, 
will depend on the resistance of the interpolar. If this 
latter be low, no " shunt " (or one of very great resistance) 
will be required; but if the resistance of the interpolar be 
very high, the resistance of the " shunt " must be corre- 
spondingly low, or else not enough current will pass to 
magnetize the field-magnet, and the dynamo w^ll give no 
current. 

Fig. 38 represents the dynamo complete. 

The machinist, mechanic, engineer, artisan, student or 
schoolboy who has not only carefully read the preceding 
pages on the dynamo, but has made.^ or attempted to make, 
a machine by closely following the ins.'ructions, will have ac- 
quired a knowledge of the rudiments of electrical science 
which will enable him to explore still further into this fasci- 
nating branch of the mechanical arts. This book is merely 
designed to start the explorer on his interesting journey; 
new discoveries, new inventions, and new surprises are daily 
events in the electrical world; but, the fundar^ental prin- 
ciples, the foundation laws, never change, and, wHh a fair 
understanding of the underlying structure, the growling fabric 
can be watched with satisfactory understanding. 

The wide-awake mechanic will endeavor to keep abreast 
with the times. He will be quick to note any novel dis- 
covery, any important innovation, and in no branch of his 
art are the possibilities of world-thrillinp sensations greater 
than in the electrical field. 

Suppose, then, that you have made a dynamo, such as 
described in this article ; suppose that you have it in active 
operation, and it is giving you a current equal to eight or ten 
Bunsen's cells; you have an instrument which wall be of the 
highest value to you in your future researches; instead of 
finding the study a laborious grind, a dry, musty. Drain 
killer, you will find yourself fascinated Vv^ith the opening 
pages of the mysterious book when it is read by the light of 
the electrical current generated by the dynamo made by the 
skill of your own hands. 

Too much value cannot be given a knowledge of the science 
of electricity and its application to the mechanical arts, in- 
creasing every day, will bring it in contact with every 
mechanic and arusan in the country. Make a dynamo as 
described, study as you make, and you will be aCle to keep 
abreast of the times. 



532 
MANAGEMENT OF DYNAMOS. 

The use of dynamos is becoming so general for electric 
lighting and power that the following hints on the manage- 
ment and care of dynamos may be of use to engineers, es- 
pecially as the care of the dynamo is usually placed in the 
hands of the engineer, and the machine placed in the engine- 
room. 

Before the dynamo is started for its day's run all the lubri- 
cators should be filled up. For this purpose none but cop- 
per oil-cans should be used. 

Next in order, the brushes should receive attention, and 
should be carefully examined to see that they are properly 
trimmed and thoroughly well screwed up to their holders. 

If the brushes touch at a bevel angle, they should be oc- 
casionally trimmed with a file, so that they will preserve an 
even bearing upon the commutator To do this properly the 
brushes should be removed from the machine. 

Never leave files or iron tools near the dynamo. If the 
machine is in a shop where iron fihngs are flying about it 
should be examined frequently to see if any filings have been 
attracted, and if any are found they should be removed. 
It is always best, if the dynamo is of necessity placed in 
such a position, that it should be boxed in as completely as 
possible. 

After the machine has been started the brushes should be 
put down; when the run is over the brushes should be raised 
before the engine is stopped. 

The commutator must be kept clean and bright and free 
from metallic dust of any kind. It should be occasionally 
wiped with a clean rag (never use waste), very slightly 
smeared with oil or vaseline; should the brushes press too 
heavily it will be worn into ruts, should they not press 
firmly enough its segments will v/ear unequally along their 
edges. 

As soon as the dynamo is started the brushes should be 
carefully so rocked that they touch at the neutral points; if 
this position is not carefully observed the sparking may 
rapidly ruin the commutator. 



533 



ELECTRICITY SIMPLIFIED. 

No one knows what electricity really is. It seems, how* 
ever, to be present everywhere. In the air, in the earth, in 
the water, in trees, animals, man, fishes, metals, everywhere, 
but no one can tell what it is. We know what steam is, for 
we can divide it into its various parts. We know what a gas 
is, for we can smell it, or taste it, or weigh it. We 
know what the air is; but we cannot see electricity, it has no 
taste, it has no weight, no substance, but it is called a forcci 
which is made known to us by the peculiar fact that it willat- 
tract or repel. 

For instance, if you take a piece of glass — a small glass 
rod or tube, and a piece of sealing-wax, and bring them near 
some small scraps of paper, or shreds of cotton, a feather, or 
gold leaf, or bran, you will not notice anything particular. 
There will be no movement of any kind. But, suppose you 
rub the glass and the sealing-wax briskly with a piece of dry 
woolen cloth, then bring them near the light substances men- 
tioned, you will find that the paper, or cotton, or gold leaf, 
or bran, or feathers, will spring or jump toward the glass rod 
or sealing-wax, even if quite a little distance is between them, 
and will cling to the glass and wax. 

You will further notice, that, after a time, the paper, etc., 
will jump away (not simply/^//) from the glass, or waj^ as if 
they had been snapped off. 

?'hus, there was so7?tething happened when the glass or 
\vdx was ruboed by the woolen cloth, something which gave 
the glass or wax the property of attracting the paper, etc. 
and afterward of repelling or casting off the same paper, etc. 

This something was the electricity excited by the friction 
between the glass or wax and the woolen cloth. 

The writer of this article is smoking an ordinary pipe, 
which has an amber mouth piece. He first wiped the moist- 
ure from the amber, and then rubbed it for a few seconds 
upon the green cloth of his desk, and, bringing it near some 
little bits of paper, he found that the paper sprang and 
remained upon the amber, ai?d, not only that, but the bit of 
paper next to the amber attracted another bit of paper, and 
that second piece another, until three little bits of paper, like 
a chain, were hanging from the amber. 

First, the amber was electrified, then each bit of paper, as 



534 

it came in contact with the electrified amber, became electri 
fied, and attractec another bit to itself. Now, there are two 
kinds of electricity, positive and negative. The positive at- 
tracts and the negative repels. This last statement can be 
easily proved. Make two little balls from the pith of the 
elder bush, or any other plant that has a dry, light pith. 
When quite dry, fasten a fine silk thread to each pith ball, 
and. suspend them from some convenient point so they will 
swing freely. 

Electrify the sealing-wax with the woolen cloth, but, elec- 
trify the glass rod witli a piece of soft silk. Touch one pith 
ball with the wax, and it will follow it for a moment and then 
shoot away, just as the paper did. At the same time touch 
the other pith ball with the glass and it will do the same 
thing. If you bring the wax and glass nearer the pith balls 
after they have been repelled, you will notice that they will 
keep away from them. Now quickly change the wax and 
glass, so that they will touch the pith ball that was first at- 
tracted and then repelled by the glass, and you will see that 
the wax will attract it, and, if you touch the other pith ball 
witk the glass, it will be attracted also. 

If you have taken the trouble to. try this simple experi- 
ment, you have learned that there is 2i positive electricity, or 
the electricity that attracts, and a negative electricity, or the 
electricity that repels. 

You have also learned that the ball which was repelled by 
the glass was attracted by the sealing-wax, and the ball that 
was repelled by the sealing-wax, was attracted by the glass. 
This proves that the electricity developed on glass is differ- 
ent in kind frovi that developed on sealing-wax, and by re- 
peating the experiment with other substances, it will be found 
that all electrified bodies act like either the glass or the sealing- 
wax. 

There is another thing, two bodies charged with (or hav- 
ing) positive electricity will repel each other, and the same 
thing will happen if the two bodies are chargeo. with negative 
electricity, but, if one is charged vix'Cci posaize^ and the other 
with 7iegative electricity, they will be attracted to each other. 

The electricity which is excited by rubbing two substances 
together is cdiW^dfrictional electricity. 

It has been shown by the above experiments that an elec- 
frified substance can impart electricity to another. This is 
called conduction. It is not necessary that the bodies should 



535 

c*ouch. They may be connectec* by a copper wire or a flax 
thread. But, if connected by a silk thread, or a piece of rub- 
ber, the electrified body will not electrify the other. Some 
substances transmit electricity readily and others do not. 

Those that offer little resistance to the passage of electricity 
are called conductors; those that offer great resistance are 
called non-conductors or insulators. Conductors which are 
held up, or wrapped in non-conductors are said to be insu^ 
lated. Silver, copper and iron are conductors. Rubber, 
gutta-percha, glass, porcelain and silk are non-conductors or 
insulators. A copper wire, if wrapped in silk or rubber, 
would be insulated. 

For practical work, conductors are made of wire, either 
copper or iron, usually having a covering made of woven silk 
or cotton. 

Frictional electricity is generated, for purposes where a 
large quantity is needed, by electric machines, which con- 
sists of a circular glass plate from one to four feet ni diaiia- 
eter, that is turned by a crank. Against the sides of this, plate 
are cushions made of silk or leather, coated with mercury. 
On turning the crank, the glass plate revolves between the 
silk cushions and is electrified. The electricity is gathered or 
caught by metal points called combs, and is carried off by 
conductors. 

Electricity is also developed by chemical action. AU chem- 
ical changes produce electric action. This is true whether the 
substance is a solid, liquid or gas, but the chemical action 
between liquids and metals gives the most satisfactory result. 
Electricity thus developed is called the Voltaic or Galvanic 
electricity. As was said before, we do not know just what 
electricity is, but we do know that by combining certain 
liquids and metals, or by making certain chemical combina- 
tions, we can make all the electricity we want. 

If we take a strip of copper and one of zinc, and place 
them in a glass jar which contains some dilute sulphuric acid 
(that is, water which has had sulphuric acid put in it), keep- 
ing the zinc and copper separated, but connecting them above 
the glass jar by a wire, conductor, we will have a current of 
electricity produced. In fact, two curreitts, opposite in kind 
and direction, are produced — but, remember that, whenever 
the direction of the electric current is referred to, it means 
the direction of i\iQ positive current. 

It is necessary, for the production of an electric curr^-<- '•? 



536 

this way, that the liquid should have a greater action upon 
one metal than upon the other. The metal which is most 
vigorously acted upon by the acid is called the positive 
plate {itgenerates^on^ might say,the electricity), the other 
is the negative plate (it collects the electricity). So the cur- 
rent starts from the positive plate, through the liquid to 
the negative plate, then out of the glass jar through the 
wire joined to the negative plate, and back through the 
other wire to the positive plate. In the apparatus de- 
scribed above(called a galvanic or voltaic element or cell) 
the zinc is the positive plate, copper the negative plate. 

The wires attached to the copper and zinc are called 
electrodes or poles. The electrode attached to the copper 
plate (which is the negative) is called the positive elec- 
trode. The one attached to the zinc plate (which is the 
positive plate), is called the negative elect'^ode. 

When two or more voltaic or galvanic elements(or cells) 
are connected together,the apparatus is called agalbanic 
or voltaic battery. In a battery the positive plate of one 
cell is connected to the negative plate of the next cell, and 
so on. When this is done, they are said to be coupled in 
series. Sometimes all of the positive plates are connected 
by wire, and all of the negative plates by another wire. 
The cells are then said to be joined in '' multiple arc." 

Batteries for producing electricity are divided into two 
classes, called "open circuit" batteries, and "closed cir- 
cuit' ' batteries. The open circuit batteries are used when 
the electricity is not required constantly, but is used for a 
short time at different periods. Such batteries are used 
with telephones, electric bells, hotel annunciators, etc. 

Closed batteries are used where the work is continu- 
ous, as for electric lights, motors, etc. 

(As galvanic cells can be readily purchased, and are not 
expensive, it is recommended that a cell for open circuit 
and one for closed circuit be purchased. For open circuit 
buy one of the following makes: Leclanche cell, or the 
Law; for closed circuit, the Grenet. These cells can now 
be bought of any electric supply store). 

Batteries as described, generating or producing elec 
tricity by the action and combination of ckemicals 
liquids and metals, are called ''Primary Batteries.'' 

There is another style of batteries, called Secondary or 
Storage batteries. A secondary battery docs not of itself 



537 

make an electric current, but is used to store up and hold the 

energy of an electric current, which is led to It from a 
primary battery or a dynamo. The electrica' energy can 
then be kept until it is wanted for use. 

A secondary or storage battery usually consists of a glass 
jar, holding plates, made of lead, and some water, which is 
made slightly acid. There are always two lead plates in a 
secondary battery, but there may be any number above that, 
and these plates are called electrodes. Upon the positive 
electrode is spread a paste made of red lead. Upon the neg- 
ative electrode is spread a paste made of litharge. 

When the plates are thus prepared, they are put into the 
acidulated water (which is held by the glass jar), and a wire 
from each plate is connected with conductors from a dynamo 
or a primary battery. When all is ready for charging, the 
current is turned on, and enters by one plate, coming out by 
the other. ' 

The electric current, of course, meets with some resistance 
from the plate and the paste, and this resistance causes it to 
work upon the paste in such a manner that a chemical change 
is made, that is, the paste on the positive electrode has been 
changed to peroxide of lead, and that in the negative electrode 
into spongy lead. 

When the current has passed from one plate to another in 
this way for a time, the wires are disconnected from the 
dynamo or primary battery. 

As the acidulated water is still left in the glass jar, the 
paste upon the plates begins to work to get back to its orig- 
inal shape, and it is this working that causes a current of 
electricity, which will light lamps, run a motor or do anything 
the current from the dynamo or primary battery would do. 

After the paste has resumed its original form, the battery 
is said to be discharged, and can then be again charged. 

It is customary, in practical use of secondary or storage 
batteries, to charge them from a dynamo. These batteries 
are largely used for street car purposes. A motor is attached 
to the axle of the car, and is energized by the storage bat- 
teries placed beneath the seats, the batteries having been 
charged from a dynamo located at the terminus of the road. 

In the article on "How to Build a Dynamo," commencing 
on page 478, the magnetizing effects of an electric current 
are explicitly explained. 



55^ 

Electricity, although it has no weight or tangible form, is 
measured as accurately as is sterdn, or air, or coal. 

The three measurements most commonly used are ; 
The Volt;^ 
The Ampere; 
The Ohm. 

The Volt is the practical unit of measurement of press- 
jtre. That is, " volP^ bears the same relation to electricity 
as " pounds " does to steam. When we speak of steam in 
a boiler or in the cylinder of a steam engine, we say: " There 
is a pressure of ten or fifty or a hundred pounds to the 
square inch," and steam pressure is calculated and measured 
in pounds; thus, a " pound " is the unit of pressure or 
intensity. 

Now, electricity moves with a certain force and pressure; 
this force is called the electro-motive force (represented by the 
letters E. M. F.), and the unit of pressure or inte^isity of this 
force, is called a volt. Thus we say that a dynamo has an 
electro-motive force of 117 volts, or that the intensity of a 
galvanic cell is l^ volts, etc. 

Suppose, instead of steam, we had used the water which 
comes into the house from the water-works, as an illustra- 
tion. That water comes in through pij^es and is forced 
through these pipes by pumps. 

Now, the water comes with a pressure of so many pounds 
to the inch, and " pound" is the unit by which this pressure 
is measured. The water would not flow through the pipes 
unless it was pushed or forced through, neither would elec- 
tricity flow through the wires without there was pressure 
back of it, and this pressure is measured in volts. 

The Ampere is the practical unit of the rate of flow of 
electricity. Electricity flows through the wire at a certain 
pressure, just as water flows through pipes at a certain 
pressure. Now, if we wanted to speak of the water coming 
through the pipes, we would say that the water was flowing 
at the rate offiYQ gallons per minute, and if the pressure on 
the water was ten pounds, we would say that the water was 
flowing at the rate of five gallons per minute, at a pressure 
of ten pounds to the inch. 

In speaking of the electric current, we say, " that a certain 
current of electricity is flowing at the rate of one ai?ipere. 
acted upon by an electro-motive force of 90 volts^ or a 
lamp requires a current of two amperes ^ at a pressure of lOO 
Zfolts to light it. 



539 

Thus, the volts of pressure forces the current to flow througli 
the wires at a certam rate per second, and this rate is called 
the a77ipere. 

The Ohm (pronounced like " ome " in home) is the practi- 
cal unit of measurement of resistance. 

Electricity is conducted or carried from one place to 
another, for the purpose of telegraphing, telephoning, light, 
power, etc., by means of wires, made of copper or iron. 

These wires do not permit the current to flow through 
them without hindrance. There is always a certain amount 
of resistance to the current, and the smaller the wire, the 
more resistance there is. Sometimes the current is too strong 
for the wire, and it becomes hot, gets red, and burns up. 

That is, the wire is too small for the volts pressure, and 
amperes of current of electricity, and the current, trying to 
get through, and fighting to overcome this resistance, becomes 
red hot and then may melt. 

This resistance is measured by the ohm; thus, a copper 
wire of such a size has a resistance of so many ohms. 



RULES AND REGULATIONS. 

FOR 

Properly Wiring and Installing Electric Light 

Plants. 

The following rules and regulations for the prevention of 
fire risks arising from electric lighting, were issued by the 
Society of Telegraph Engineers and Electricians of England, 
and every person, connected with an establishment using 
electric lights, whether owners or employes, should care- 
fully read them, and be governed thereby % 

The chief difficulties which beset the electrical engineer are 
internal and invisible, and can only be effectually guarded 
against by testing with special apparatus, and electric cur- 
rents. They arise from leakage and bad connections and 
joints, which lead to waste of energy and the production of 
heat to a dangerous extent. 

Moisture Danger. — The necessity for guarding against 
the presence of moisture, which leads to loss of current and 
to the destruction of the conductors and apparatus, by cor- 
rosion and otherwise, cannot be too strongly urged. 



y/LO 

Earth Danger. — Injudicious connections of any part of 
tfte circuit with the "earth" tend to magnify every other 
source of difficulty and danger. 

Ignorance and Injudicious Economy. — Many of the 
dangers in the appUcation of electricity arise from ignorance 
and inexperience on the part of those who supply and fit up 
inadequate plants, and frequently from injudicious economy 
on the part of the user. 

Safety in Consulting Experienced Engineers.— 
The greatest element of safety is, therefore, the employment 
of skilled and experienced electrical engineers to specify the 
method in which the work is to be done, and ihe quality of 
the materials to be employed, and to supervise the execution 
of the work. 

CONDUCTORS. 

1. Sectional Area. — Conductors (wires) must have a 
sectional area and conductivity so porportioned to the work 
they have to do, that, if double the current proposed is sent 
through them, the temperature of such conductors shall nof 
exceed 150° Fahr. 

2. Accessibility. — The conductors, or their coverings, 
should be placed in sight, if possible, and they should always 
be as accessible as circumstances will permit. 

3. Insulating. — Within buildings they should be insu- 
lated; and this rule applies equally to all conductors and 
parts of fittings which may have to be handled. 

4. Maximum Temperature.— Whatever insulating mate- 
rial is employed it should not soften until a temperature 
of 170° Fahr., has been reached, and, in all cases, the material 
must be damp-proof. 

5. Casings. — When wires pass through roofs, floors, 
walls or partitions, and where they cross, or are liable to touch 
metallic substances, such as bell wires, iron girders, or pipes 
they should be thoroughly protected by suitable addi^iiona' 
covering; and, where they are liable to abrasion from an 



541 

cause, or the depredations of rats or mice, they should be 
encased in some suitable hard material. 

6. Distance Apart. — Conductors should be kept as far 
apart as circumstances will permit, the spacing between them 
being governed by their potential difference. 

7. Inflammable Structures. — When conductors are 
carried in very inflammable structures, precaution should be 
taken to isolate them therefrom. 

8. Metallic Armor. — Conductors which are protected 
on the outside by lead, or metallic armor of any kind, require 
the greatest care in fixing, on account of the large conducting 
surface which would become connected to the core in the 
event of metallic contact be^^ween them. 

9. Joints. — All joints must be mechanically and electrically 
perfect, to prevent heat being generated at these points. 
When soldering fluids are used in ma,king joints, the latter 
should be carefully washed and dried before insulation is 
applied. 

10. Gas and Water Pipes. — Under all circumstances 
complete metal circuits must be employed. Gas and water 
pipes must never form part of a circuit, as their joints are 
rarely electrically good, and therefore become a source of 
danger. 

11. Overhead Conductors. — Overhead conductors, 
whether passing over or attached to buildings, must be insu- 
lated at their points of support. 

Precaution must be taken to obviate all risks of short-cir- 
cuiting, where they are likely to touch a building, or other 
overhead conductors and wires, either by their own fall or 
by being fallen upon by other conductors. 

12. Lightning Protector. — In the case of overhead 
wires, every main should have a lightning protector at each 
point, where it enters or branches into a building. 



542 

13- Insulation Resistance. — The insulation of i syr^iem 
of distribution should be such, that the greatest leakage from 
any conductor to earth (and, in case of parallel w orkmg, from 
one conductor to the other, when all branches are switched 
on, but the lamps, motors, etc., removed), does not exceed 
one Jive thousandth part {-^^^^ of the total current intended for 
the supply of the said lamps, motors, etc., the test being 
made at the usual working electro-motive force. 



SWITCHES. 

14. Construction and Action. — Every switch or com- 
mutator should be of such construction as to comply with 
the following condition, namely: That when the handle is 
moved or turned to or from the positions of " on " and " off," 
it is impossible for it to remain in any intermediate position, 
or to permit of a permanent arc, or heating. 

15. Insulated Handles.— The handles of every switch 
must be completely insulated from the circuit. 

16. Main Switches, Pqsition of. — The main switches 
of a building should be placed as near as possible to the point 
of entrance of the conductors, or to the generators of the cur- 
rent if they are within the building itself. Sv/itches should 
be provided on both leads. 

17. Switch Boards. — Switch boards should bear clear 
instructions for their use by the inexperienced. 



ELECTRICAL FITTINGS GENERALLY. 

18. Bases. — Switches, commutators, resistances, bare 
connections, lamps, etc., mast be mounted on incombustible 
bases; cut-outs, mounted on bases of wood, rendered unin- 
flammable, are admissible; vulcanite bases are undesirable in 
damp situations. The cracking of porcelain and earthen- 
ware fittings is a source of danger which can be avoided by 
precautions in fixing. 



543 
CUT-OUTS. 

19. Imperative Use of. — All circuits should be protected 
by cut-outs ; and all leads from the mains, or small conductors 
from larger ones, must be fitted with cut-outs at their branch- 
ing pomts 

20. Situation. — Where fusible cut-outs are used, the 
section should be so situated within ijts frame that the fused 
metal cannot fall where it may cause a " short circuit " or an 
ignition. 

21. For ( + ) AND ( — ) Mains. — For all main conductors 
a cut-out should be provided for both the " flow " and 
"return;" and the two fusible sections must not be in the 
same compartment. 

22. For Portable Fittings. — The flexible wires of por- 
table fittings must in all cases be protected by cut-outs at 
their fixed points of connection. 



ARC LAMPS. 

23. Globes, etc. — Arc lamps must always be guarded by 
globes, netted or otherwise, so to prevent danger from 
ascending sparks, or from falling glass and incandescent 
pieces of carbon. 

24. Insulation of Parts. — All parts of the lanips and 
lanterns which are liable to be handled (except by the persons 
employed to trim them), should be insulated. 

THE DYNAMO. 

25. Insulation, Situation, etc. — The armatures and 
field magnet coils should be thoroughly insulated. Dynamos 
should always be fixed in dry places, and they must not be 
exposed to dust flyings or other industrial waste products 
carried in suspension in the a.r. They should not be per- 



544 

mitted in the working rooms of mills, where the liability to 
such dangers exists, or, where any inflammable manufactures 
are carried on, or inflammable materials are stored. 

26. Motors. — Motors should be subject to the same con- 
ditions; but when it is necessary to use them in positions such 
as those above referred to, they must be securely cased in, 
such cases having a n on -combustible lining. 



BATTERIES. 

27. Insulation. — Both primary and secondary batteries 
should be placed and used under the same precautions as pre- 
scribed for dynamos; and the room in which they are placed 
should be well ventilated. The batteries themselves must be 
well insulated. 



MAINTENANCE. 



28. Testing. — The value of frequently testing and inspect- 
ing the apparatus and circuits cannot be too strongly urged as 
a precaution against fire. Records should be kept of all tests, 
so that any gradual deterioration of the system may be 
detected. 

29. Cleanliness. — Cleanliness of all^parts of the appara- 
tus and fittings is essential to good maintenance. 

30. Repairs. — No repairs or alterations must be made 
when the current is " on." 



GENERAL. 

All the above rules for the reduction to a minimum of the 
risks from fire, are also applicable in principle to installations 
of electricity for other uses than that of lighting : they also 
include precautions necessary to avoid risks of injury to per- 
sons, whether the conductors and apparatus are situated 
inside or outside a building. 



545 



DEFINITIONS OF ELECTRICAL AND 
MECHANICAL TERMS. 



ABSOLUTE TEMPERATURE.— Temperature as reck- 
oned from the absolute zero, which is 461.2 degrees 
below the Fahrenheit zero. 

ACCELERATION.— Rate of change of velocity. 

ACCUMULATOR. — i. Any apparatus which increases the 
current strength, as a dynamo electric machine. 2. A 
secondary storage battery. 3. A condenser. 

ACCUMULATOR, CHARGING.— Sending an electric 
current into a storage battery for the purpose of render- 
ing it an electric source. 

ACTION, LINES OF INDUCTIVE.— i. Lines of elec- 
trostatic force. 2. Lines within the space, separating a 
charge and neighboring body, along which electrostatic 
induction takes place. ^> 

ACTION, LOCAL, OF VOLTAIC CELL.— A waste of 
energy. Consumption of the zinc, or positive element of 
a voltai ccell, when the circuit is open or closed, or in 
regularly. 

ACTIVITY, UNIT OF.— Rate of doing work. One unit 
of work performed in one unit of time equals one unit of 
activity. In C. G. S. system, unit of activity equals 
one erg per second. Practical unit in same system is the 
watt, equal to one joule per second. In British system, 
unit of activity is the horse power, equal to 550 foot- 
pounds per second or 33,000 foot-pounds per minute. 
The ratio between the two systems is i H. P. = 746 
watts (about). 

ADDENDUM. — That part of the tooth of a gear wheel 
which extends outward from and beyond the pitch line. 

ADHERENCE, MAGNETIC. —Adhesion between sur- 
faces due to magnetic attraction. 

ADIABATIC EXPANSION OF A GAS.— The expansion 
when no heat is given to or taken away while so doing. 

ADJUSTABLE REAMER.— A reamer the teeth of which 
1 may be adjusted to the necessary diameter. 

ADMISSION. — Point of stroke at which steam is admitted 
to a steam cylinder. 



S4^ 

/iDMISSION LINE.— The line traced on an indicatov 

card from beginning of stroke to point of cut-off. 
AIR BLAST FOR COMMUTATOR.— A device to pre- 
vent th'e injurious action of destructive flashes at the 
commutator of a dynamo electric machine. 
AIR PUMP. — The pump used to remove air and water 

from a condenser. 
AIR THERMOMETER. — One generally made of glass 
tubing in which the expansion and contraction of a cer- 
tain volume of air raises and lowers a column of water, 
and this, by a suitable scale, indicates the temperature. 
ALLEN VALVE. — An ordinary D valve with an interior 

passage allowing steam to be admitted at two places. 
ALLOYS. — A few of the more important combinations 
are : 

Solder, plumber's; tin 66 parts, lead 34 parts. 

Pewter, hard; tin 92 parts, lead 8 parts. 

Britania Metal; tin 87 parts, antimony 8 parts, copper 

4 parts, bismuth I part. 
Type Metal; lead 80, antimony 20 parts. 
Brass, white; copper 65, zinc 35. 
Brass, red; copper 90, zinc, 10 parts. 
Speculum Metal; copper 67, tin 33 parts. 
Bell Metal; copper 78, tin 22 parts. 
Aluminum Bronze; copper 90, aluminum 10 parts. 
German silver; copper 50, zinc 25, nickel 25 parts. 
Pailard Palladium; copper 15, palladium 60,. iron I 

part. 
Platinum Silver; platinum I, silver 2 parts. 
ALTERNATION.— A to-and-fro motion. Changes in the 

direction of a current. 
ALTERNATIONS, COMPLETE.— A complete to-and-fro 

change. 
ALTERNATIONS, FREQUENCY OF.— The number of 

alternations in unit time or per second. 
ALTERNATOR. — An alternating current dynamo. A re- 
versing commutator. 
ALTERNATOR, COMPENSATED EXCITATION OF. 
— An excitation of an alternating current machine, in 
which the field is but partially excited by separate excite- 
ment, the remainder of its exciting current being derived 
from the commuted currents of the machine itself. 
AMALGAM. — A mixture of metal with mercury applied 
to rubbers of frictional electrical machines. 



547 

■^.MMETER. — A form of galvanometer for measuring the 
current strength of amperes. 

AMMETER, GRAVITY. — One in which a magnetic 
needle moves against the force of gravity. 

AMMETER, MAGNETIC-VANE.— A fixed and a mova- 
ble vane in the field, which repel each other and so 
measure the current. 

AMMETER, PERMANENT MAGNET. — A magnetic 
needle moved against the field of a permanent magnet. 

AMPERE. — The unit of electric current. That current 
which can be driven by the pressure of one volt, the unit 
of electromotive force, throup-h one ohm, the unit of 
electrical f"esistance. Such a rate of flow of electricity 
as transmits one coulomb per second. A current of such 
strength as would deposit .ro5o84 grains of copper per 
second. The unit rate of flow per second. 

AMPERE FEET. — The product of the current in amperes 
by the distance in feet. 

AMPERE HOUR. — Equal to one ampere flowing for one 
hour, or 3600 coulombs. 

AMPERE-VOLT.— A watt or 746 of i H. P. The follow^ 
ing expression signifies that C, the current in amperes, is 
equal to E, the electro-motive force in volts, divided by 

E 
R, the resistance in, ohms: C= — . This is Ohm's law. 

R 

AMPERE'S RULE FOR CURRENT EFFECTS ON 
NEEDLE. A magnetic needle if placed near a current 
of electricity flowing from the observer, who is facing 
the needle, is deflected to his left. 

ANEMOMETER. — An apparatus to electrically record the 
direction of the wind. 

ANGLE OF LAP. — Angle through which eccentric must 
be turned to admit steam at beginning of stroke when 
the lap is added to a valve. 

ANGLE OF LEAD. — Angle through which an the eccentric 
is turned to give lead to a valve. 

ANGLE -TOOTH. — A gear wheel tooth which runs across 
the face of a wheel in a line that develops part of the 
circumference of the wheel. 

ANNEALING. — The heating of metals, glass, etc., to a 
high degree and cooling slowly. To temper or soften. 

ANNUNCIATOR.— A device for indicating the place a;* 
which electric circuits have. been closed. 



548 

ANODE. — ^The positive terminal of an electric source, in 
opposition to Kathode, the negative terminal. 

APRON. — I. In an iron planer, the piece that carries the 
tool post or clamp. 2. Applied to parts which act as a 
shield. 

ARBOR. — A mandrel. A shaft or spindle. 

ARC. — I. The source of light of the electric arc lamp. 
The bow of light which appears betvreen two electrodes. 
An arc formed between two electrodes. 2. A section or 
part of, a circle. 

ARC OF APPROACH.— The arch (measured on the pitch 
circles) covered from the time any one pair of teeth of 
two gear wheels come ii. to contact until the point of con- 
tact is on the line of centers. 

ARC, COMPOUND.— An arc formed between more than 
two electrodes. 

ARC OF PITCH.— The pitch of gear wheel teeth from 
measurement around the pitch circle. 

ARC OF RECESS.— The arc (measured on the pitch cir- 
cles) covered from the time the point of contact of any 
one pair of teeth of two gear wheels is on the center 
line, until they leave contact. 

ARC, WATT. — ^The energy required to maintain a given 
arc or candle power. 

ARM. — I. One of the paths of an electric balance. 2. A 
support for insulators carrying electric coils. 3. A mov- 
able sign employed as a signal on railroads. 

^RM, ROCKER. — An arm on which the brushes of a 
dynamo or motor are mounted for the purpose of shifting 
their position on the commutot'or. 

ARMATURE. — The coils of insulated wire together with 
the iron armature core, on which the coils are wound. 
A mass of iron or other magnetizable material placed on 
or near the pole of a mbgnet. The iron sheathing of a 
cable. I 

ARMATURE, BI-POLAR.— An armature of a dynamo 
electric machine, the polarity of which is reversed twice 
in every revolution. 

ARMATURE, DRUM.— One in which the armature core 
is solid, or nearly so, the wires being wound longitudi- 
nally along the core and across the ends. 

ARMATURE, NON-POLARIZED.— An armature of soft 
iron which is attracted, whatever the direction of the 
current. 



549 

ARMATURE, POLARIZED.— Having a polarity inde- 
pendent of that imparted by the magnetic pole. 

ARMATURE, RING.— An armature, the coils of which 
are wound on a ring-shaped core. 

ARMATURE, UNIPOLAR.— An armature, the polarity 
of which is not reversed during its rotation. 

ASTATIC. — Standing, or possessing no direct power. Not 
opposed to the earth's magnetism, 

B 

B. — A symbol for internal magnetization. 

BACK-GEAR. — The gears on the back of the head-stock 
of a lathe which can be thrown in or out to change the 
speed. 

BACK-KNIFE GAUGE LATHE.— A lathe in which the 
work is finished and cut to desired shape by a knife at its 
back. 

BACK PRESSURE.— Pressured caused on the back side 
of the piston by the exhaust steam. 

BALL AND SOCKET JOINT.— A joint consisting of a 
ball in a socket which encases it, but permits it to be 
moved in the casing; a universal joint. 

BALL-PENE. — The spherical pene of a hammer. 

BAND-SAW. — An endless steel band having saw-teeth on 
one edge and run on pulleys like a belt. 

BARS, OMNIBUS OR BUS.— The bars carrying the cur- 
rent from an electric generating plant. 

BASTARD FILE.— A file, the teeth of which are coarser 
than those of a second-cut file and finer than those of a 
coarse-cut file, the difference usually being one grade or 
degree. 

BATTERY. — The combination of a number of separate 
electric sources, as two or more voltaic cells or series of 
cells coupled together. 

BATTERY, DYNAMO.— The coupling together of sev- 
eral dynamo-electric machines. 

BATTERY, MAGNETIC— The combination as a single 
magnet or a number of separate magnets. 

BATTERY, OPEN CIRCUIT.— A battery through which 
the circuit is closed only when transmitting signals. 

BATTERY, PLUNGE.— A number of separate cells con- 
nected so as to form a single source and be simultane- 
ously placed or plunged in the exciting liquid. 



550 

BEARING,— A rest for a shaft or rod which holds it in 

position. 
BELT-SHIPPER.— A shipper used to move a belt from 

one pulley to another, 
BELT-TIGHTENER.— A pulley employed for tightening 
a belt on another pulley, and used to cause the belt to 
transmit power periodically instead of continuously. 
BEVEL-GEAR. — A gear wheel whose teeth are at an angle 

to its shaft. 
BLAST-PIPE.— A pipe conveyieg the air-blast to a cupola 

or other furnace. 
BLOW OFF.— The opening generally at the lowest point 

in a boiler where the boiler is to be emptied. 
BOARD, HANGER, — A su^Dporting and connecting plate 

for arc lamps. 
BOARD, SWITCH. —A board provided with switches 

which open, close or interchange circuits. 
BOBBIN.— An insulated coil of wire for an electro-magnet, 
BOILER STAYS.— Rods or bars or plates put in in such a 

way as to guy or stay flat surfaces to other parts. 
BOILER, TUBULAR, — One containing a large number 

of small tubes through which gases from the fire pass, 
BOILER, WATER TUBE. — One made up of a large 

number of small tubes in which water circulates. 
BOLT.— Metal rod having a head on one end and a threaded 

stem to receive a nut at the other; used for holding. 
BORE. — The inside of a cylinder. 

BORING-BAR. — A bar that drives boring or cuttine; tools 
BORING-MACHINE.— A machine for boring holes in 

metal or other material, 
BOSS.— A raised portion about a hole through which a bolt, 

screw, pin or shaft passes. 
BOTTOMING-TAP.— A tap with a thread up to its extreme 

end so that it will cut a thread to the bottom of a hole. 
BOURDON PRESSURE GAUGE.— The ordinary steam 
gauge m which the pointer is moved by the pressure act- 
mg inside a curved tube of elliptical cross section which 
it tends to straighten. 
BOX-CHUCK.— A two-jawed chuck used in finishing brass. 
BOX, DISTRIBUTION OR JUNCTION.— A manhole in 
an electric conduit at the junction of lead or other win^s. 
BOX-TOOL. — A tool for use in screw machines and turret 
>^ heads which guides the work. It often carries more than 
one cutting tool. 



55i 

BOX -WRENCH. — A wrench which fits endwise over the 
head o-f a bolt. 

BRAKE, ELECTRO-MAGNETIC— An electro-magnetic 
brake for car wheels. 

BRAKE, PRONY OR FRICTION.— A mechanical device 
for measuring the power of a driving shaft. 

BREAK OR GAP LATHE.— A lathe whose bed beneath 
plate is cut out out so as to permit work of large dia- 
meter to be swung. 

BRIDGE. — An apparatus for balancing or measuring ele- 
trical resistance. 

BRIDGE WALL.— The wall just back of the grate of a 
boiler furnace reaching up close to boiler and causing 
flame to hug the boiler. 

BRIDGE OF VALVE SEAT.— The thickness of metal 
between the exhaust and steam ports of a steam engine. 

BRUSH. — Strips of metal, bundles of wire, plates of car- 
bon, etc., that bear on the commutator cylinder of a 
dynamo-electric machine, and carry the current from and 
to it. 

BRUSH LEAD. — The moving forward of the brushes in 
the direction of rotation to get the best output and 
reduce sparking. 

BUCKLING. — Irregularities or bending of the plates of 
storage cells, sometimes due to a too rapid discharge. 

BUNTER-DOG. — A work-gripping tool for a planing 
machine, consisting of a piece having a hook end to 
engage in the T-slot of the table and a set-screw to bind 
the work. 

BUTT-JOINT. — A riveted joint in which the ends of the 
plate or material abut directly; distinguished from a lap 
or other form of joint. 

BUTTON, CARBON.— A carbon resistance in the shape 
of a button. 

BUTT-STRAP.— A band, usually of iron, for holding to- 
gether the pieces in a butt-joint. 

BUTT-WELD. — A weld in which the two pieces abut 
when put together to weld, as distinguished from a lap or 
other form of weld. 

C 

CABLE, CAPACITY OF.— The quantity of electricity 
required to raise a given length of cable to a given poten- 
tial, or given difference of potential. 



552 

CALIBRATE. — ^To determine the relative value of the 
scale divisions or of the indications of a measuring 
device, as a galvanometer, voltmeter or ammeter. 

CALORIC.~A heat unit. 

CALORIMETER.— An instrument by which the amount 
of moisture in steam is determined. 

CAM. — A disk whose surface is not a true circle, which ac- 
tuates other parts by revolving. 

CANDLE POWER.— The unit of photometric intensity. 
A light equal to that produced by a standard candle. 

CAPACITY. — Such a capacity of a condenser or conductor 
that an electromotive force of one volt will charge it 
with a quantity of electricity equal to one coulomb. 

CAP-SCREW. — A square-headed screw with a collar. 

CARBONS, ARTIFICIAL.— Carbon obtained by the car- 
bonization of a mixture of pulverized carbon with differ- 
ent carbonizable liquids. 

CARBON, GORED.— A cylindrical carbon electrode for 
an arc lamp that is molded around a central core of 
charcoal, or soft carbon. 

CASE-HARDENING.— A process for hardening the sur- 
face of wrought iron, the hardened surface being about 
1-32" deep. 

CAT-HEAD. — A sleeve running in a bearing and screwed 
to light lathe work to steady it. 

CAULKING. — ^The upsetting of the edges of the plates 
near riveted joints, thus making the joints tight. 

CELL, BICHROMATE.— A zinc-carbon couple, in a solu- 
tion of bichromate of potash and sulphuric acid in water. 

CELL, BUNSEN'S. — A zinc-carbon couple, immersed re- 
spectively, the zinc in dilute sulphuric acid and the car- 
bon in nitric acid. 

CELL, DANIELL'S. — A zinc-copper couple immersed, 
the zinc in dilute sulphuric rcid and the copper in a sul- 
phate of copper solution. 

CELL, GRAVITY. — A zinc-copper couple in solution of 
zinc sulphate and saturated solution of sulphate of copper. 

CELL, GROVE. — A zinc-platinum couple in sulphuric 
and nitric acid respectively. 

CELL, LECLANCHE. — A zinc-carbon couple in sal- 
ammoniac. 

CELL, POROUS. — A jar of unglazed earthenware, em- 
ployed in double fluid voltaic cells, to keep the two 
liquids separate. 



553 

CELL, SELENIUM. — A cell consisting of a mass of sele- 
nium fused in between two conducting wires or electrodes. 

CELL, SMEE — Zinc-silver couple in dilute sulphuric acid. 

CELL,, STORAGE. — A cell made of two relatively inert 
metal plates, immersed in an electrolyte, that stores elec- 
tric energy when passed into it, and reproduces same 
when connected externally. 

CELL, VOLTAIC. — The combination of two metals which 
when dipped into an electrolyte and connected outside the 
liquid by a conductor will produce a current of electricity. 

CENTRIFUGAL FORCE.— Force canised by a body tend- 
ing to fly off at a tangent when revolving in a circle. 

CHANGE-GEARS. — The gear wheels which are used tc 
change the revolutions of a feed or lead screw. 

CHASER, — A tool for cutting threads in a lathe by hand. 

CHECK-NUT. — An additional nut screwed against the 
first to check the tendency to worl^ back. 

CHISEL-TOOTH SAW.— A saw ^ ith inserted teeth hav- 
ing a heavy front rake. 

CHUCK. — A tool to hold work in a lathe or device to hold 
another tool, as a drill-chuck. 

CHUCK-PLATE.— A face plate constructed so that work 
can be chucked on it. 

CIRCUIT, CONSTANT POTENTIAL.— A circuit the 
potential of which remains constant. 

CIRCUIT, EARTH.— A circuit in which the ground forms 
the return path. 

CIRCUIT, METALLIC— A circuit in which metallic con- 
ductors are alone employed, and ground is not used for 
return. 

CIRCUIT, MULTIPLE, Multiple-arc-parallel or Quantity. 
— ^Two or more generators or receptive devices having 
their positive poles connected to one conductor and all 
their negative poles connected to a second conductor. 

CIRCUIT, MULTIPLE-SERIES.— Two or more groups 
of electrical apparatus connected in multiple, the sepa- 
rate parts of each group being connected in series. 

CIRCUIT SERIES. — A compound circuit, as a chain, in 
which the sources, or receptive devices form links and are 
so arranged that the current must pass successively 
through from the first to the last. 

CIRCUIT, SHUNT. — A branch, by-path or second cir- 
cuit of comparatively high resistance through which a 
portion of the circuit flows. 



554 

CIRCULATING PUMP.— The pump employed to drive 
the cooling water through a condenser. 

CLEARANCE. — The volume included between the piston 
and the valve seat when the piston is at the end of its 
stroke. 

CLEMENTS-DRIVER.— A device for driving workk in a 
lathe, which equalizes the strain on the two ends of the 
carrier or dog. 

CLUTCH. — An engaging and disengaging device which 
enables motion to be communicated from one part to an- 
other, or the same to be stopped. 

COG. — A wooden tooth for a gear wheel. 

COIL, CHOKING OR IMPEDENCE.— A coil of iron so 
wound on a core of iron as to possess high self-induction. 

COIL, INDUCTION, RHUMKORFF. — Two parallel 
coils of insulated wire employed for the production of 
currents by mutual induction. 

COIL, PRIMARY. — The coil or conductor of an induction 
coil or transformer through which the rapidly interrupted 
ar alternating primary or inducing current is sent. 

COIL, SECONDARY.— That coil of an induction coil or 
transformer in which currents are induced by alternations 
or interruptions of the current passed through the primary 
coil. 

COILS. ARMATURE. OF DYNAMO-ELECTRIC MA- 
CHINE. — The conductor wound or placed on the arma- 
ture. 

COLD, PRODUCTION OF, BY ELECTRICITY.— When 
an electric current passes across a thermo-electric junc- 
tion, the junction is either heated or cooled, according to 
the direction of the current. 

COLLAPSING-TAP.— A tap so formed that its teeth close 
inwards when the thread is cut. permitting the tap to be 
withdrawn without winding it backward. 

COMBINATION-CHUCK.— A chuck so constructed that 
the jaws may be moved either simultaneously or indivi- 
dually. 

COMMUTATOR, DYNAMO-ELECTRIC MACHINE.— 
That part of a dynamo-electric machine which is designed 
to cause the alternating currents produced in the armature 
to flow in one and the same direction in the external circuit. 

COMPOUND-GEARS.— A train of gear wheels in which 

) two wheels of different diameters are fixed on one shaft 

so that the vek^city may be varied. ^ 



555 

COMPOUND SLIDE-REST.— A slide-rest with two slides, 
one above the other. 

COMPRESSION. —The pressure caused at the end of 
stroke by closing the exhaust port. 

COMPRESSION LINE.— The line traced on an indicator 
card from the time the exhaust port is closed to the begin- 
ning of the stroke. 

CONDENSATION, INITIAL.— The condensation which 
takes place when steam enters the cylinder at the begin- 
ning of each stroke. 

CONDENSEP.. — I. Cooling apparatus for condensing ex- 
haust steam. 2. (Leyden jar). Device for increasing the 
capacity of an insulated conductor; and induction device. 

CONDENSER, CAPACITY OF,— The quantity of elec- 
tricity in coulombs a condenser is capable of holding 
before its potential in volts is raised to a given amount. 

CONDENSER, SURFACE. — One in which the steam 
comes in contact with surfaces cooled by air or water. 

CONE-BEARING. — A journal bearing which has a second 
sleeve that may be moved endvv^ise to take up wear. 

CONE-MANDREL. — A mandrel which employs two cones 
to hold hollow work. 

CONE-PLATE. — A device with a coned mouth which sup- 
ports one end of work in a lathe, thereby steadying it. 

CONTACT-BREAKER, AUTOMATIC— A device for 
causing an electric current to rapidly make and break 
its own circuit. 

CONTROLLER. — An automatic magnetic regulator for a 
dynamotelectric machine. 

CONVERSION, EFFICIENCY OF, OF DYNAMO.— 
The total electricity energy develop by a dynamo, divided 
by the total mechanical energy required to drive the 
dynamo. 

CONVERTER. — The inverted transformer or induction coil 
used on alternating current systems. 

CORE, ARMATURE OF DYNAMO-ELECTRIC MA- 
CHINE. — Iron core on or around which the armature 
coils of a dynamo-electric machine are wound or placed. 

CORE, ARMATURE, LAMINATION OF. — A subdi- 
vided core in separate insulated plates or strips for the 
purpose of avoiding eddy currents. 

CORE, ARMATURE, VENTILATION OF.— Means for 
passing air through the armature core of a dynamo-elec- 
tric machine in order to reduce the heating. 



5ii6 

CORE. LAMINATIONS OF.— Structural subdivisions of 
the cores of magnets. 

CORE, SOLENOID. — A core so arranged as to be drawn 
into a solenoid on the passage of the current through the 
coils. 

COULOMB. — The unit of electrical quantity. That quan- 
tity of electricity which would pass in one second through 
a resistance of one ohm with a pressure of one volt. 

COUNTER-SHAFT.— A small shaft with pulleys upon it, 
one usually being an idler, to permit a machine to be 
started and stopped without stopping the main shaft or 
driving belt, and also to vary the speed of the machine. 

COUNTERSINK. — A tool for cutting an enlargement, 
cone-shaped or perpendicular, at the mouth of a hole. 

COUPLE, ASTATIC— Two magnets of equal strength 
suspended one over the other in the same vertical plane 
so as to completely neutralize each other. 

COUPLE, THERMO-ELECTRIC,— Two dissimilar met- 
als which, when connected at their ends only so as to 
form a complete circuit and one of the ends is heated, 
will produce an electric current. 

COUPLE, VOLTAIC, GALVANIC,— Two dissimilar met- 
als in an electrolyte and capable of producing an electric 
current. 

C. P. — Contraction for candle power. 

CRANK. — Arm which turns the engine shaft of an engine. 

CRANK-PIN.— The pin in end of the crank to which the 
connecting rod is attached. 

CROSSING, LIVE TROLLEY.— A device whereby a trol- 
ley moving over a line that crosses a second line at an 
angle is enabled to maintain its electrical connection with 
the line while crossing. 

CROWK-WHEEL. — A gear wheel whose teeth are on its 
side face. 

CURRENT DENSITY.— The current which passes in any 
part of a circuit as compared with the area of cross-sec- 
tion of that part of the circuit. 

CURRENT, ELECTRIC— The quantity of electricity 
which passes per second through any conductor or circuit. 

CURRENT, GENERATION OF BY DYNAMO-ELEC- 
TRIC MACHINE.— The difference of potential devel- 
oped in the armature coil by the cutting of the lines of 
magnetic force of the field by the coils during the rota- 
tion of the armature. 



557 

CURRENT, INDUCED.— The current produced in a con- 
ductor by cutting lines of force. 

CURRENT, ROTATING.— Term applied to a current which 
results by combining a number of alternating currents 
whose places are displaced with respect to one another. 

CURRENT STRENGTH.— The product obtained by di- 
viding the electro-motive force by the resistance. Accord- 
ing to ohm's law. the strength for a constant current is: 
E (electromotive force) 

C (current) == 

R (resistance) 

CURRENT, TRANSFORMING A.— Changing the elec- 
tromotive force of a current by its passage through a con- 
verter or transformer. 

CURRENT UNIT, STRENGTH OF.— Such a strength 
of current that when passed through a circuit one centi- 
meter in length, arranged in an arc one centimeter in 
radius, will exert a force, of one dyne on a unit magnet 
pole placed at the center, equal to ten amperes. 

CURRENTS, EDDY.— Useless currents produced in the 
pole pieces, armatures and field-magnet cores of dynamo 
electric machines or motors. 

CURRENTS, SIMPLE PERIODIC. — Alternating cur 
rents. A current of such a nature that the continuous 
variation of the flow past any cross section of the con- 
ductor, or the variation in the electro-motive force of 
which can be expressed by a simple, periodic curve. 

CURRENTS, UNDULATORY.— Currents, the strength 
and direction of whose flow gradually changes. 

CURVE, CHARACTERISTIC — A diagram in which a 
curve is employed to represent the ratio of certain vary- 
ing values. 

CUSHIONING. — The closing of the exhaust port before 
the end of the stroke to allow the steam thus enclosed to 
take up the shock of reciprocating parts. 

CUT-OFF. — The point of stroke at which the steam port 
is closed. 

CUT-OUT. — A device that will remove an electro-receptive 
device from the circuit. 

CUT-OUT, T0.< — ^To remove an electro-receptive device 
rrom the circuit of an electric source by disconnecting oi 
diverting the circuit from it. 

CYCLOID. — A curve generated by a pencil fixed in the 
perimeter of a circle when rolled upon another circle. 



55» 

CYCLE, MAGNETIC— Single round of magnetic charges 
to which a magnetizable substance is subjected when it 
is magnetized from zero to a certain maximum and then 
decreased to zero and so on. 

D 

DAMPER. — A retarding device: A metallic device sur- 
rounding the core of an induction coil for the purpose of 
varying the intensity of the induced currents. 

DAMPER, ARC-LAMP.— The dash-pot or other device 
offering resistance to quick motion. 

DEAD-BEAT. — A swinging magnetic needle which is 
quickly brought to rest. Such a motion of a galvano. 
meter needle in which the needle moves sharply over the 
scale from point to point and comes quickly to rest. 

DEAD-POINT ) Position of crank-pin when piston rod, 
or >• connecting rod, and crank are in a 

DEAD-CENTER. ) straight line. 

DECLINATION, ANGLE OF.— The angle which meas- 
ures the deviation of the magnetic needle from the true 
geographical north. 

DEKA (AS A PREFIX). —Ten times, as deka-ampere. 

DEMAGNETIZATION.— A process by which a magnet is 
deprived of its magnetism. 

DENSITY. ELECTRIC— The quantity of free electricity 
an any unit of area or furface. 

DEPOLARIZATION.— Depriving a voltaic cell of its 
polarization. 

DEPOSIT, ELECTRO-METALLURGICAL.— The de- 
posit of metal by the process of electro-metallurgy. 

DETECTOR, GROUND.— A device in an incandescent 
lamp-system for showing the location of a ground. 

DEVICE, ELECTRO-RECEPTIVE.— Any device placed 
in an electric circuit and energized by the current, such 
as motors, telegraphs and telephones, lamps, transform- 
ers, etc. 

DIAMAGNETIC. — The reverse to magnetic attraction; 
metals, etc., which are repelled by the poles of magnets 
are called diamagnetic. 

DIAPHRAGM. — A plate or sheet securely fixed at its 
edges, as a drum head, and capable of being set in vibra- 
ti<-^n, as a telephone diaphragm. -^ 



559 

DIELECTRIC, — A substance which permits induction to 
take place through its mass. 

DIMMER. — A choking coil employed on transformer cir- 
cuits to regulate the potential. 

DIP, MAGNETIC. — Deviation of a magnetic needle from a 
true horizontal position. Its inclination towards the earth. 

DISC, ARAGO'S. — A non-magnetic metal disc, as of cop- 
per, which, when rapidly rotated under a freely supported 
magnetic needle, will cause the needle to be deflected or 
to rotate. 

DISC, FARADAY'S. — Anon-magnetic metal disc fixed on 
an axis parallel to the direction of the magnetic field in 
which it is to move. 

DISCHARGE. — To equalize the potential. The equaliza- 
tion of the difference of potential by metalically con- 
necting the terminals. 

DISCHARGE, BRUSH.— A faintly luminous discharge 
that occurs from a pointed positive conductor. 

DISCHARGE, OSCILLATING. — Successive discharges 
and recharges which occur on the disruptive discharge of 
a condenser. 

DISCHARGE, VELOCITY OF.— The time required for 
the passage of a discharge through a given length of 
conductor. 

DISTRIBUTION, CENTER OF.— In electrical engineer- 
ing, any place in a system of multiple-distiibution where 
branch cut-outs and switches are located. 

DOG. — A device for holding or steadying w^ork. 

DOG-HEAD. — A hammer for straightening saw or other 
plates. 

DOME. — The upright cylindrical drum attached directly 
to a boiler; used as a steam-chamber. 

DOUBLE-DECK BOILER.— One composed of two cylin- 
drical shells placed vertically above each other. 

DRIFT-PIN. — The punch-like tool driven into rivet holes 
when the holes of two plates do not coincide. 

DROP-HAMMER. — A hammer for forgin^g, stamping or 
other work, which is raised by power and falls by gravity. 

DRUM. — A cylindrical chamber connected in some way 
to the main boiler. 

DOUBLE SLIDE-REST.— A feed motion in which there 
^are two slide-rests on one slide-way. 

DUTY. — The amount of work done by an engine as com- 
pared with the work or fuel consumed. 



DYNAMO, INDUCTOR. — A dynamo machine for alter- 
nating currents in which the difference of potential caus- 
ing the currents is obtained by magnetic changes in the 
cores of the armature and field coils by the movement 
past them of laminated masses of iron inductors. 

DYNAMO, POLYPHASE.— A dynamo from which two 
or more alternating currents are taken. 

DYNAMO, ROTARY-PHASE.— Rotating current dynamo. 

DYNAMO, SEPARATELY-EXGITED.— Dynamo whose 
fields are separately excited. 

DYNAMOMETER.— Instrument for measuring power. 

DYNAMOMETER, ELECTRO.— A form of galvanometer 
for the measuring of electric currents. 

DYNE.— The unit of force. The force which, in one sec- 
ond, can impart a velocity of one centimetre per second 
to a mass of one gramme. 



EARTH OR GROUND.— A plate buried in the ground to 
make connection between line and earth where the earth 
is used as the return circuit. A fault in a line caused by 
its contact with the earth. That part of the earth which 
forms part of an electric circuit. 

ECCENTRIC— A disk placed off the center on a shaft. 

ECCENTRIC, THROW OFF.— Amount of offset given 
an eccentric. 

EFFECT, FERRANTI. — A difference of potential of 
mains towards their ends furthest from the terminals con- 
nected with a source of constant potential. 

EFFECT, HALL.— The Hall effect is produced by plac- 
ing a thin, metallic strip, conveying an electric current, 
in a strong, magnetic field. A transverse electromotive 
force, produced by a magnetic field in substances under- 
going electric displacement. 

EFFECT, JOULE.— The beating effect produced by the 
passage of an electric current through a conductor. 

EFFECT, THERMO-ELECTRIC— The production of an 
electromotive force at a thermo-electric junction by a 
difference of temperature. 

EFFECT, THOMSON.— The production of an electro- 
motive force in unequally heated homogeneous conduct- 
ing substances. 



56i 

EFFECT, VOLTAIC— A difference of potential at the 
point of contact of the two dissimilar metals. 

EFFICIENCY, BOILER.— Ratio of total amount of heat 
in the steam given out by a boiler to the total heat given 
out by the fuel. 

EFFICIENCY, COMMERCIAL OF DYNAMO. —The 
available electrical energy in the external circuit, divided 
by the total mechanical energy required to drive the 
dynamo that produced it. 

EFFICIENCY, ELECTRIC— The useful electrical energy 
of anv source, divided by the total electrical energy. 

EFFICIENCY, ENGINE. — Ratio of amount of energy 
given out by an engine in the form of work to total 
amount of energy given to the engine in the form of heat 
in the steam. 

EFFICIENCY, QUANTITY, OF STORAGE BATTERY. 
The ratio of the number of ampere-hours taken out of a 
secondary battery, to the number of ampere hours put in 
the battery in charging it. 

EFFICIENCY, REAL, OF STORAGE BATTERY.— 
The ratio of the number of watt-hours taken out of a 
storage battery, to the number of watt-hours put into the 
battery in charging it. 

ELECTRICITY, DISTRIBUTION OF, BY ALTER- 
NATING CURRENTS.— A system of electric distribu- 
tion by the use of alternating currents, transformed before 
passing through lamps, motors, etc. 

ELECTRICITY, DISTRIBUTION OF, BY CONSTANT 
CURRENTS. — A system for the distribution of electri- 
city by means of direct i. e. continuous, steady or non- 
alternating currents. 

ELECTRICITY, DISTRIBUTION OF, BY CONTINU- 
OUS CURRENTS, BY MEANS OF TRANSFORM- 
ERS. — A system for the transmission of electric energy 
by means of direct currents that are sent over the line 
to stations where motor-dynamos are used for trans- 
formers. 

ELECTRICITY, MAGNETO. —Electricity produced by 
the motion of magnets past conductors, or of conductors 
past magnets. 

ELECTRICITY, NEGATIVE. — The kind of electric 
charge produced on rosin when rubbed with cotton. The 
opposite to positive electricity. 



5^2 

ELECTRICITY, POSITIVE.— The kind of electric charge 
produced on cotton when rubbed against rosin. 

ELECTRICITY, STATIC— A term applied to electricity 
produced by friction. 

ELECTRICITY, THERMO. — Electricity produced by 
difference of temperature of dissimilar metals. 

ELECTRICITY, UNIT OF QUANTITY. —The current 
of electricity conveyed by unit current per second. The 
coulomb which is the quantity conveyed by a current of 
one ampere in one second. 

ELECTRODE. — The terminals of an electric source. 

ELECTRODES, CARBON, FOR ARC LAMPS.— Rods 
of artificial carbon employed in arc lamps. 

ELECTROLYSIS. — Chemical decomposition effected by 
means of an electric current. 

ELECTROLYTE, POLARIZATION OF. —When the 
poles of all the molecules of any chain are turned in the 
same direction, viz: with their positive poles facing the 
negative Dlate, and the negative poles facing the positive 
plate. 

ELECTROMETER, QUADRANT.— An electrometer in 
which an electrostatic charge is measured by the attract- 
ive and repulsive force of four plates or quadrants, on a 
light needle suspended within them. 

ELECTROSCOPE. — An apparatus for indicating the pres- 
ence of an electric charge and determining whether the 
charge is positive or negative. 

ELECTROSCOPE, GOLD-LEAF.— An electroscope em- 
ploying two leaves of gold to detect the presence and 
polarity of a charge, 

ELECTROSTATICS.— That which treats of the phenom- 
ena and measurement of electric charges. 

ELECTROTYPE. — An impression consisting of a thin 
shell, or coating of metal, usually copper, deposited on a 
plate by means of electro metallurgy, being afterwards 
backed by soft metal. 

ELEMENT. — Matter that is composed of but one kind of 
atoms and cannot be decomposed into simpler matter. 

ENERGIZING, ELECTRICALLY.— An effect caused by 
electricity in an electro-receptive device, as energizing an 
electro-magnet by passing current through the coils. 

ENERGY, ELECTRIC— The power which electricity 
posseses of doing work. The current in amperes, multi- 
plied by the differential of potential in volts, divided by 



563 

74^, equals the rate of doing work in horse-power. 746 
volt amperes, or watts, equals one horse-power. 

ENERGY, ELECTRIC, TRANSMISSION OF.— The 
transmission of mechanical energy between two distant 
points connected by an electric conductor, by converting 
the mechanical energy into electrical energy at one point, 
sending the current so produced through the conductor, 
and reconverting the electrical into mechanical energy at 
the other point. 

ENERGY, POTENTIAL OR STATIC— Energy possess- 
ing the power of doing work, but not actually perform- 
ing such work. Stored energy, or the power of doing 
work by a body at rest. 

ENGINE, BLAST.— One used to force a blast of air, as 
for a blast furnace. 

ENGINE, COMPOUND.— One in which the same steam 
is used in two or more cylinders. 

ENGINE, CONDENSING.— One in which the exhaust 
steam, is condensed back into water. 

ENGINE, DOUBLE, TRIPLE, QUADRUPLE, EX- 
PANSION. One in which the same steam is used in 2, 
3 and 4 cylinders respectively. 

EQUATOR, MAGNETIC. — An irregular line passing 
through the earth approximately midway between the 
earth's magnetic poles. 

EQUIVALENCE, CHEMICAL. —The quotient obtained 
by dividing the atomic weight of any elementary sub- 
stance by its atomicity. That quantity of an elementary 
substance that is capable of combining with or replacing 
one atom of hydrogen. 

EQUIVALENCE, ELECTRO-CHEMICAL.-'^The chemi- 
cal equivalent of a substance multiplied by the electro- 
chemical equivalent of hydrogen. 

EQUIVALENCE, ELECTRO-CHEMICAL, LOSS OF. 
— ^The amount of chemical action produced by an elec- 
tric current, passed through various chemical substances, 
is proportional to the chemical equivalent of each sub- 
stance. 

ERG. — ^The work done when a body is moved through a 
distance of one centimeter with the force of one dyn^. 
A dyne centimetero 

EVAPORATION, ELECTRIC— The formation of vapors 
at the surface of substances by the iofluence of negative 
electrification. 



5^4 

EXPANDING CHUCK.^ -A chuck that usually holds work 
from its bore and is capable of expanding to adjust itself 
to a difference in diameter of a piece of work. 

EXPANDING-MANDREL.— Mandrel whose diameter may 
be varied, generally constructed with adjustable jaws. 

EXPANSION-JOINT.— A joint placed in a pipe to allow 
the same to expand and contract under changes in 
temperature. 

EXPLODER, ELECTRIC MINE OR ELECTRO-MAG- 
NETIC. — A magneto-electric machine used to produce 
the currents of high electro-motive force employed in the 
direct firing of blasts. 

EXTENSION LATHE.— A lathe with a bed in two longi- 
ttidinal parts so that the upper one supporting the carriage 
may be moved from the face-plate, leaving a gap and 
permitting work of larger diameter to be chucked. 



FACE-CAM. — A cam whose actuating surface is on its 

side or sides. 
FARAD. — The practical unit of electric capacity. 
FEATHERING PADDLE WHEEL.— One in which the 

floats are raised out of the water edgewise. 
FEED, CHECK-VALVE.— The valve placed in the feed 

pipe of a boiler to prevent water from leaking back 

through the pump or injector. 
FEED, CLOCKWORK FOR ARC LAMPS.— An auto- 

matically started arrangement of clockwork for obtaining 

a uniform feed motion of one or both electrodes of an 

arc lamp. 
FEED-MOTOR.— The part of a machine which feeds 

either the tool or the work, so that a cut may be made. 
FEED-WATER HEATER.— A sort of boiler generally 

heated by exhaust steam through, which feed water for a 

boiler is passed for the purpose of heating it. 
FENCE. — A plate in a machine to hold work in position. 
FIDDLE-DRILL.— A drill that is revolved back and forth 

by means of a bow with a string to it. 
FIELD, AIR. — That portion of a magnetic field in which 

the lines of force pass through air only. 
FIELD, ALTERNATING, MAGNETIC— A magnetic 

field the direction of whose lines of force is alternately 

reversed. 



565 

FIELD, ELECTRO-MAGNETIC.^The space traversed 
by the magnetic force produced by an electro-magnet. 

FIELD, ELECTROSTATIC— The region of electrostatic 
influence surrounding a charged body. 

FIELD, MAGNETIC— The region of magnetic influence 
surrounding the poles of a magnet. 

FIELD, MAGNETIC, ALTERNATING.— The magnetic 
field produced by an alternating current. 

FIELD, MAGNETIC, REVERSING. — That portion of 
the field of a dynamo-electric machine, produced by the 
field-magnet coils, in which the currents flowing in the 
armature coils are stopped or reversed after the coil has 
passed its theoretical position of neutrality. 

FIFTH-WHEEL.— The circular slideway which permits 
the front axle of a vehicle to be turned horizontally. 

FILLISTER-HEAD.— A cylindrical serew-head that con- 
tains a screw-slot. 

FINDER-WIRE, — Galvanometer used to locate the corre- 
ponding ends of different wires in a bunched cable, 

FIRE-BOX. — ^The chamber or box containing the fire in all 
boilers in which the same is surrounded by water. 

FIT-STRIP. — A projection about an inrh in width for the 
purpose of being fitted to bed a piece properly, to obvi- 
ate bedding the entire surface of the piece. 

FLAT-CHISEL. — A machinist's chisel, wedge-shaped. 

FLAT-DRILL. — A drill of rectangular cross-section. 

FLATTER. — A swage for plane or flat surfaces. 

FLEXIBLE-SHAFT.— A wire shaft constructed similar to 
wire rope, for transmitting rotary motion. It may be 
bent and still perform its oflice. 

FLUX or FLOW, MAGNETIC— The total number of 
magnetic force in any magnetic field. 

FLY-WHEEL. — ^The wheel with a heavy rim placed on an 
engine shaft to give a steady motion to the engine. 

FOLLOW-BOARD.— A piece constructed to fit a pattern, 
to prevent the latter from warping. 

FOLLOW-REST.— A rest which steadies work on a lathe 
and travels with the carriage. 

FOOT-BLOCK. — A work-holding device with a dead cen- 
ter, for use on a milling machine. 

FOOT-POUND.— The unit of work. The amount of work 
required to raise a pound vertically through a distance 
of one foot. 



St)0 

FORCE, CENTRIFUGAL.— Force that is supposed to urge 
li. rotating body directly away from the center of rotation. 

FORCE, CONTACT.— A difference of electrostatic poten- 
tial produced by the contact of dissimilar metals. 

FORCE, ELECTROMOTIVE. ABSOLUTE UNIT OF. 
— A unit of electromotive force, expressed in absolute or 
C. G. S. units. The one-hundred millionth part of a volt. 

FORCE, ELECTROMOTIVE, COUNTER OR BACK. 
— A reverse electromotive force, which tends to cause a 
current in the opposite direction to that actually produced 
by the source. 

FORCE ELECTROMOTIVE, COUNTER OF MUTU- 
AL INDUCTION. — The counter electromotive force 
produced in the primary circuit of an induction coil by 
the action thereon of a simple-periodic e. m. f. 

FORCE, EI ECTROMOTIVE, DIRECT.— An e. m. f . act- 
ing ni the Same direction as another e. m. f . already existing. 

FORCE, ELECTROMOTIVE, IMPRESSED.— The e. 
m. f. acting on any circuit to produce a current therein. 

FORCE, ELECTROMOTIVE, SIMPLE PERIODIC.-^ 
An e. m. f . which varies in such manner as to produce a 
simple-periodic current, or an e. m. f., the variations of 
which are correctly represented by a simple-periodic curve. 

FORCE, ELECTROSTATIC, LINES OF.— Lines ex- 
tending in the direction in which the force of electro' 
static attraction or repulsion acts. 

FORCE, MAGNETO-MOTIVE.— That difference of mag- 
netic potential or magnetic pressure existing in a magnetic 
circuit which creates the magnetic lines of force. 

FORCE, MAGNETO-MOTIVE. PRACTICAL UNIT 
OF. — A value of the magneto-motive force equal to 
All 

=1.25564 times the amperes of one turn. (The 

10 

Greek letter pi is used in engineering as the symbol for 
ratio of circumference to diameter, i. e., 3.1416; the 
diameter multiplied by // equals circumference. 

FORCED-DRAUGHT.— Forcing of air through a furnace 
by means other than the natural draught of a chimney. 

FORK, TROLLEY. — The mechanism connecting the trol- 
ley-wheel mechanism to the trolley pole. 

FORMER. — A piece that guides or controls the movement 
of a cutting tool; also a template to which pieces are 
shaped. 



5^7 

FRICTION-GEARING. —Wheels which transmit motion 
by frictional contact on their circumference. 

FROG, TROLLEY. — A device employed in fastening 
together trolley wires where they branch off, and as a 
guide to the trolley wheel. 

FURNACE, ELECTRIC— An electrically heated furnace, 
employed for the purpose of effecting difficult fusion. 

FUSIBLE-PLUG,— Plugs of metal placed in holes in the 
parts of a boiler exposed to the highest heat whicli 
would melt before the plates could be injured by heat. 



GALVANIC ACTION or ) Corroding of plates and stays 

VOLTAIC ACTION. f supposed to be caused by elec- 

tric currents being generated by the impurities in water 
acting on the plates, especially where copper is used. 

GALVANOMETER. — An apparatus for measurmg the 
strength of an electric current. 

GALVANOMETER, ASTATIC— One having two needles 
so arranged that the earth's magnetism has little or no 
effect on them. 

GALVANOMETER, BALLISTIC— A galvanometer de- 
signed to measure the strength of a current that lasts but 
for a moment, such, for example, as the current caused 
by the discharge of a condenser. 

GALVANOMETER, DIFFERENTIAL.— A galvanometer 
containing two coils so wound as to tend to deflect t':e 
needle in opposite directions. 

GALVANOMETER, MARINE.— A galvanometer for use 
on steam ships where the motion of magnetized masses 
of iron would seriously disturb the needles of ordinary 
instruments. 

GALVANOMETER, MIRROR OR REFLECTING.— A 
galvanometer in which instead of reading the deflections 
of the needle directly by its movement, over a graduated 
scale, thep are read by the movement of a spot of light 
reflected from a mirror attached to the needle. 

GALVANOMETER, VOLTMETER.— An instrument for 
the measuring of differences of electrical potential. 

GANG-MILLS. — Milling machine cutters placed side by 
side on the gangs. 

GAP, AIR. — An opening or gap in a magnetic circuit coi> 
taining air ohly. 



568 

GAP-LATHE. — A lathe having a gap in its bed to permit 
work to be chucked which would not otherwise clear the 
guides. 

GAUGE-COCK. — A stop cock placed at different levels on 
a boiler; the level of the water being determined by the 
issuing of steam or water from it. 

GAUGE, WIRE, MICROMETER.— A micrometer gauge 
employed for measuring the diameter of a wire in thou 
sandths of an inch. 

GAUGES, WIRE, VARIETIES OF.— The principal wire 
gauges in use are given in the following table: There are 
three standards as follows: Brown & Sharp, or Ameri- 
can; Birmingham or Stub's; English Legal Standard. 
An idea of the gauges compared, can be had from the 
following (the diameter of the wire is given in mills) : 

No. o No. lo No. 30 

Gauges. Wire. Wire. Wire. 

B. & S 324.86 101.89 10.925 

Birmingham. . .^ 340. 134. 12. 

English Standard 324. 128. 12. 4 

GEAR-WHEELo — A wheel provided with teeth for engag- 
ing with those of a similar wheel. 

GENERATOR, DYNAMO-ELECTRIC— A machine in 
which electricity is produced by the movement of con- 
ductors through a magnetic field in such a manner as to 
cut the lines of force. A Dynamo-electric machine. 

GOOSE-NECK. — A frame constituting a fulcrum for a 
rachet brace. 

GOVERNOR. — A device for maintaining constant the 
speed of a steam engine or other prime mover, despite 
sudden changes in load. 

GOVERNOR, CENTRIFUGAL.— One which depends for 
its action upon the change in the centrifugal force ex- 
erted upon certain of its parts due to change of speed. 

GOVERNOR, FLY-WHEEL OR SHAFT.— One used on 
automatic engine? and contained in the fly or belt wheel 
and connected to the eccentric. 

GRAMME. — A unit of weight in the metric system, equal 
to 15,43235 grains. Also written Gram. 

GRAVIS. — A hand tool of rectangular cross section having 
cutting edges at its end, which are formed by grinding 
^the end face at an acute angle to the body of the tool. 



569 

GRID. — A lead plate, provided with perforations employed 
in storage cells for the support of the active material. 

GROUND. — Contact of an electric conductor with the earth. 

GROUND RETURN.— A term applied when the earth is 
used as part of an electric circuit. 

GUIDE-BAR. — A bar on which slides a moving or recipro- 
cating part, as an engine's cross-head. 

GUM. — The bottom section between saw teeth. 

GUSSET-STAYS. — Triangular shaped stays made of boiler 
plate used for such places as staying the eijd of a boiler 
to the side. 

H 

HALF-CHECK JOINT.— A joint in which a piece is let 

into another so that the surface comes level. 
HAMMER-TEST. — Test of a boiler made by hammering 

the plates, defects being located by the sound. 
HAND-HOLE. — The holes placed in the sides of a boiler 

large enough to admit the hand for cleaning, etc. 
HEAD-END. — End of the cylinder away from the crank. 
HEAT OF EVAPORATION.— Amount of heat necessary 

at a given pressure to turn a unit of water into dry steam. 

HEAT, MECHANICAL EQUIVALENT OF. — The 

; amount of mechanical energy converted into heat. The 

mchanical equivalent of one unit of heat is equal to 772 

foot pounds of work. 
HEAT, SPECIFIC— The capacity of a body for heat 

compared with that of an equal quantity of some other 

substance, usually water. 
HEAT UNIT (BRITISH).— The quantity of heat required 

to raised the temperature of a pound of water from 32 

to 33 degrees Fahrenheit. 
HEATING-SURFACE.— The surface plates of a steam 

boiler which receive the flame or heat on one side and 

which have water on the reverse side. 
HINDLEY'S SCREW.— Short length of screw, sometime: 

called an endless screw, used to drive a worm wheel. 
HORSE POWER (H. P.).— A commercial unit for power 

or rate of doing work. A rate of doing work equal to 

raising 550 pounds one foot in one second, or 33,000 

pounds one foot in one minute, and always involveing the 

three factors, force, distance and time. 
HOUR LAMP. — A service of electric current which will 

maintain one electric lamp yne hour. 



570 

HOUR, WATT. — An expenditure of one watt for one 

hour. A unit of electrical work. 
HUNTING-TOOTH.— An extra tooth placed in a pair of 

gear wheels to vary the number of teeth, so that the same 

teeth will not always engage together. 
HYPOCYCLOID.— A cycloidal curve in which the rolling 

circle is rolled within the buse (or fixed) circle. 

I 

IMPEDANCE. — The sum of all resistance, ohmic and 
spurious, in a circuit, expressed in ohms. 

INCLINATION, ANGLE OF.— The angle of magnetic 
dip. The angle which a magnetic needle, free to move 
in a vertical and horizontal plane, makes with a horizon- 
tal line passing through its point of support. 

INDEX-PLATE. —A circular disk divided (generally by 
holes bored in its face) so that a complete circumference 
or 360"^ may by equally divided into any number of 
parts, within the limits of the plate. 

INDICATOR — An instrument for recording the pressure in 
a cylinder at each point of the stroke. 

INDICATOR, SPEED.— A device for indicating the revo- 
lutions per minute of a shaft or machinery. A tachometer. 

INDUCTION. — The influence which a charged body or 
■ magnetic field exerts on bodies near but not in contact 
with it. 

INDUCTION, ELECTROSTATIC— The charge produced 
when a conductor enters an electrostatic field. 

INDUCTION, MAGNETIC. —The magnetization in a 
magnetic field of any magnetizable substance. 

INDUCTION, SELF, CO-EFFICIENT OF.— The quan- 
tity of induction passing through a circuit per unit cur- 
rent in the circuit. 

INSULATION OR INSULATOR.— A non-conductor of 
electric current, used to prevent leakage of current. 

INTENSITY, PHOTOMETRIC, UNIT OF.— The light 
produced by the consumption in a wax candle of two 
grains of spermaceti wax per minute. 

INVOLUTE. — Curve formed by the path of a given point 
in a straight line when the line is rolled upon a circle. 

IONS. — The products of decomposition in any given elec- 
trolysis ; those adhering to the positive are Kathion and 
to the negative Anion. 



571 

IRON-WORK FAULT OF DYNAMO. —The short-cir- 
cuiting of a dynamo by improper contact between its 
coils and any iron. 

ISOCHRONISM.— Equality of the periods of vibration. 

ISOTHERMAL EXPANSION. — Expansion of a gas 
where its temperature is kept constant by supplying heat 
externally. 



JACKET. — An annular space around a cylinder. 

JAR, LEYDEN. — A static condenser in the form of a jar. 
The coatings of metal are placed on the lower exterior 
and interior walls, about two-thirds the depth of the jar, 
the rest being varnished or shellacked. It has a cork cover 
through which a brass rod extends making contact with 
its interior. The rod has a ball on top. 

JOINTS OF BELTS, BUTT AND LAP.— The butt joint 
in a belt is one in which the two ends are cut square, 
brought together so that they abutt directly and laced. 
In the lap joint the ends are overlapped and laced or 
riveted through. 

JOULE. — The practical C. G. S. unit of electrical energy 
or work. One joule = 10,000,000 ergs. One joule per 
second = i watt. 

JOURNAL. — The part of a shaft that runs in a bearing or 
journal box. 

K 

KATHODE OR CATHODE.— The terminal connected to 
the negative or carbon plate of an electrolytic cell. 

KEY, DISCHARGE AND CHARGE.— A key by the 
use of which the discharge from a condenser is passed 
through a galvanometer for measurement. 

KILODYNE.— One thousand dynes. 

KILOGRAMME. — One thousand grammes. About 21-5 
pounds avoirdupois. 

KINETICS, ELECTRO.— Electric currrents, or electricity 
in motion, in contradistinction with electrostatics, or elec- 
tricity at rest. 

KNURLING OR MILLING TOOL.— A tool to form in- 

^ dentations or corrugations upon the surfaces of metal 
pa-rts so that the hand may grip the part more securely. 



tl^ 



LAG, ANGLE OF.— The angle describing the shifting of 
the magnetic axis of the armature core of a dynamo, 
caused by the resistance of the core to the sudden revers- 
als of magnetism. 

LAG, MAGNETIC— The viscosity of iron or steel, which 
renders it slow to take up and part with magnetism. 
This sluggishness is one of the causes necessitating 
**lead" of the brushes. 

LAMP, INCANDESCENT, STRAIGHT-FILAMENT.— 
Lamp with a straight filament, rendered luminous by high 
frequency electrostatic waves. It is the invention of Tesla. 

LAMP, INCANDESCENT, THREE-FILAMENT.— An 
incandescent lamp provided withe three filaments and 
three leacling-ii? wires connected thereto. It is used on 
three-phase circuits. 

LANTERN. — A form of gear of early practice in which 
rungs are employed in place of teeth. 

LAP. — Projection of the valve beyond the ports when in 
mid-position. 

LATENT HEAT. — Heat which is used up in changing the 
molecular condition of a body without changing its tem- 
perature, as in changing ice at 32 degrees to water at 32 
degrees, and water at 212 degrees to steam at 212 degrees 
Fahrenheit. 

LAW OF JACOBL— The work of an electric motor is at its 
maximum when the counter e. m. f. is equal to half the 
e. m. f . expended on the motor, or the impressed e. m. f. 

LAW OF JOULE. — A current heating power is propor- 
tional to the product of the square of the current strength 
and the resistance. 

LAW OF OHM.— The funda^nental law of the relations 
between current, e. m. f . and resistance in an electric cir- 
cuit, or the law of current strength. The strength of a 
continuous current is directly proportional to the e. m. f. 
in the circuit, and inversely proportion to the resistance 
in it, or the e. m. f . divided by the resistance, The alge- 
braic expression for Ohm's law is 
C (current) _ E (electromotive force)^ ^^ ^^^ ^^ .^ ^^^ 

R (resistance) 
of the other two factors, we have: E = C R, or C X R; 

and for a similar expression for R, we have, R=« — -. 



573 

LAW OF VOLTA.— A law for the e. m. f. between dissi- 
milar metals in an electro chemical series. It is: **The 
difference of potential between any two metals is equal 
to the sum of the differences of potential between the 
intervening substances in the contact series." 

LAWS OF COULOMB, OF ELECTROSTATIC AT- 
TRACTION AND REPULSION.— I. The attractions 
and repulsions between two bodies electrified are in in- 
verse ratio of the square of their distance. 2. The force 
of attraction or repulsion between two electrified bodies 
is directly as the product of the quantities of electricity 
they are charged with, the distance remaining the same. 

LAWS OF FARADAY.— Laws expressing the effects of 
electrolysis. 

LAWS OF JOULE.— Laws for the development of heat 
in electric circuits. 

LAWS, LENZ'S. — The rules for determining the directions 
of currents produced by electro-dynamic induction for- 
mulated by Lenz. 

LEG. — A wire used on a telephone switchboard for placing 
one subscriber in circuit with two or more telephones. 

LIGHTING, ELECTRIC, BY HIGH FREQUENCY.— 
A system invented by Tesla, in which rods of carbon or 
other refractory substances are placed in an electrostatic 
field rapidly alternating, and raised to incandescence. 

LINE-SHAFT. — Shaft that receives motion directly from an 
engine or other motor, and transmits it to various points. 

LINES, KAPP. — Proposed as a unit for lines of magnetic 
force, I Kapp line to equal 6,000 C. G. S. units. 

LINES, VORTEX-STREAM.— Lines whick extend in the 
direction of the motion of the particles of a fluid. 

LINK. — The curved slotted piece to which the two eccen- 
tric rods are attached on a reversing engine. 

LIQUID, ELECTROPOION. — A liquid for a battery, 
composed as follows: 2^ pounds of sulphuric acid are 
placed in 10 pounds of water, in which I pound of bicro- 
mate of potash is dissolved. 

LOAD, LIQUID. — Resistance, or load, made by placing the 
terminals of a dynamo in water, which completes the circuit. 

LOG, ELECTRIC. — An electric indicator for measuring 
the speed of a ship. 

LOOP, DRIP. — A pendant or downward loop formed in 
electric wires immediately before entering a building to 
prev^it the passage of water on the wire into the building. 



5/4 

LUBRICATOR. — A cup arranged to feed oil to rubbing 
surfaces and into the steam which is being supplied to an 
engine. 

M 

MACHINE, DYNAMO-ELECTRIC— Device or machine 
by means of which mechanical power is transformed into 
electric by magneto electric induction, or by which electric 
is converted into mechanical power, the latter being called 
a motor. Such a machine consists, first, of a circuit of iron, 
made up of frame, pole pieces and an armature core 
which rotates between the pole pieces as close to their 
faces as practicable; second, coils of copper wire around 
the iron poles, which, when energized by an electric cur- 
rent, make electromagnets or fields of the poles and 
cause a magnetic circuit to flow through the poles and 
armature core; third, coils of copper wdre wound around 
the armature core, which, on being rotated, cut the mag- 
netic lines of force and develop electromotive force; 
fourth, a collecting device connected with the armature, 
called a commutator in direct current machines; fifth, 
brushes of copper or carbon resting on this collecting 
cylinder which carry off the current generated. 

MACHINE, DYNAMO, ALTERNATING CURRENT. 
— A dynamo which produces alternating currents for 
work. It is an ordinary dynamo the currents from which 
are not commuted or made to flow in one direction by 
means of a commutator. The field are usually separately 
excited, as a direct current is required for their excitation. 

MACHINE, DYNAMO, OUTPUT OF. —The current 
generated in and put out by a dynamo, measured in 
watts, or kilowatts. 

MACHINE, DYNAMO, SEPARATELY-EXCITED.— A 
dynamo w^hose field coils receive current for their excita- 
tion from some source other than its own armature. They 
are usually alternating current dynamos. 

MACHINE, DYNAMO, SHUNT.— A dynamo in which 
part of the current goes through the fields to excite them. 
There are two leads from the brushes, one to the fields 
and one to the outside circuit. The fields are wound in 
shunt with the outside circuit. A shunt and separately- 
excited dynam.o is compound-wound, one field coil receiv- 
ing curreet from the armature, the other from a separate 
source. 



575 

MAGHINE, ELECTROSTATIC INDUCTION. A ma- 
chine having a rapidly rotating disc of electric substance. 
A small charge is greatly increased by its inductive ac- 
tion on the disc. 

MACHINE, MAGNETO-ELECTRIC— A machine simi- 
lar to a dynamo, except that the fields are permanent 
magnets instead of electro-magnets. 

MACHINE, TOEPPLER, HOLTZ.— A changed form of 
the electrostatic induction machine devised by Holtz. 

MAGNET, COMPENSATING.— A magnet placed above 
a magnetic needle, usually of a galvanometer, so as to 
counteract the action on said needle of the metal in that 
vicinity. 

MAGNET, CONTROLLING.— A magnet which has con- 
trol over a certain action : as one attached to a galvano- 
meter to regulate the directive tendency of the magnetic 
needle. 

MAGNET, ELECTRO.— Magnetizable material, usually 
soft iron, magnetized by surrounding with a coil or. insu- 
lated wire through which a current of electricity is passed. 
The wire is called the helix and the iron the core. The 
electro-magnet loses its magnetism upon the cessation 
of the magnetizing current. 

MAGNET, FIELD. — A magnet employed to produce the 
field in dynamo-electric machines. 

MAGNET, RELAY.— A magnet used in telegraphy to 
cause a local battery to act at the receiving station. Its 
coils are connected to the main line. 

MAGNET, TABULAR. —Iron-clad horseshoe magnet in 
which a tube is employed, to increase its liftingpower. 

MAGNETISM, AMPERE'S THEORY OF. —A theory 
advanced by Ampere accounting for the phenomena of 
magnetism. It assumes the presence of currents in the 
atoms of matter. 

MAGNETISM, ANIMAL. — Sometimes applied to mes- 
merism, hypnotism and similar manifestations of occult 
power. 

MAGNETISM, EWING'S THEORY OF.— A hypothesis 
to account for magnetism, advanced by Prof. Ewing. 

MAGNETISM, RESIDUAL. — Magnetism remaining in 
magnetizable material after it is removed from a magnet- 
izing field is residual magnetism, but the term is restricted 
to that which remains in soft iron cores of electromagnets 
after the circuit is broken. 



57& 

MAGNETISM, TERRESTRIAL.— Magnetism of the earth. 

MAGNETITE. — That which, when magnetized, forms 
lodestone. Magnetic oxide of iron. 

MAGNETIZATION.— Causing material to partake of mag- 
netic properties. 

MAGNETIZATION, CO-EFFICIENT OF. — A number 
that represents the strength or intensity of magnetization 
divided by the magnetizing force H. 

MAGNETIZATION, INTENSITY OF.— The amount of 
magnetism present in a magnetizable substance, expressed 
in magnetic lines of force. 

MAGNETOMETER.— A form of reflecting galvanometer, 
used particularly for measuring the intensity of the 
earth's field. 

MAIN, ELECTRIC. — The most important conductor in any 
electric distributive system, either of lighting or power. 

MANDREL. — A bar, or arbor, usually round, which is 
driven into work, or on which work is driven, for revolv- 
ing it in a lathe. 

MANGLE-WHEEL.— A gear wheel, the teeth of which 
are arranged so that the wheel moves back and forth 
without making a complete revolution. 

MANOMETER. — An apparatus used in ascertaining the 
tension of gases, either in atmospheres or inches of mer- 
cury. There are two kinds: mercurial and metallic. 

MASS, UNIT OF. — One cubic centimeter of water at 39 
degrees F. is the C. G. S. unit of mass. 

MATCHER OR MATCHING-MACHINE, — A machine 
which cuts a groove on one edge of a board and a tongue 
on the other edge. 

MATERIALS, INSULATING. — Substances, usually sol- 
ids, such as rubber, fiber, mica, etc., which, on account 
of their high non-conducting properties ase used to insu- 
late electric conductors to prevent leakage. 

MECHANICAL, EQUIVALENT OF HEAT.— Number 
of units of work which, by means of friction or other- 
wise, will produce one unit of heat. 772 foot-pounds of 
work are equivalent to one unit of heat. 

MEDIUM, ELECTRO-MAGNETIC— The universal or 
luminiferous ether through which electro-magnetic waves 
are propagated. 

MEG OR MEGA. — Used as a prefix to mean i,ooo.cxXJ 
times; as, megadyne, 1,000,000 dynes. 



577 

MERCURY-GAUGE. — A gauge for measuring pressure of 
gases by balancing this pressure by a column of mercury 
in a tube. 

MERIDIAN, MAGNETIC.— The magnetic meridian may 
be regarded as the vertical plane in which a freely sus- 
pended magnetic needle comes to rest in the earth's mag- 
netic field. 

METALLURGY, ELECTRO.— The science of electrical 
reduction or treatment of metals. 

METER, ELECTRIC. — An instrument for measuring the 
quantity (or amperes), or the pressure (or voltage) of an 
electric current. 

METRE-MILLIMETRE.— A unit of length for resistances, 
having a cross-section of one square millimetre and a 
length of one metre. It may be of any material. 

MICRO. — One millionth part, as microvolt, one millionth 
part of a volt. 

MICROMETER.— A small tool, finely graduated, for meas- 
uring with accuracy small distances, usually in thou- 
sandths or ten-thousandths of an inch. 

MICROPHONE. — A device for multiplying the vibrations 
of sound waves, so as to render a faint or distant sound 
audible. Used in telephony as transmitters. 

MICROTASIMETER.— A device for indicating minute at- 
mospheric changes of temperature and moisture. 

MIL. — A unit of length used in measuring the diameter of 
wires. It is one-thousandth (.001) part of a lineal inch. 

MILE, STANDARD. — A standard of resistance employed 
by Matthiessen. It is I mile of copper wire 1-16 inch in 
diameter at 15.5 degrees C. 

MILLI-CALORIE.— The small calorie. Amoimt of heat 
necessary to raise one gramme of water from zero to I 
degree C. 

MILLING-MACHINE. — A machine in which revolving 
cutters are used to cut, shape and dress metal. 

MITER-JOINT.— A joint whose angle to the plane of the 
piece it joins is 45 degrees. 

MOTOR, ELECTRIC. — A machine for converting electri- 
cal into mechanical energy, by passing an electric current 
through it. The discovery that the armature of a dyna- 
mo will rotate when a current is passed through it, was 
one of the most important in electrical science. 

MOTOR, ELECTRIC, ALTERNATING-CURRENT.— 
An electric motor operated by an alternating current o^ 



578 

electricity. There are two kinds: one being an ordinary 
alternating current dynamo reversed, the other Tesla's or 
Thomson's. 

MOTOR, PYROMAGNETIC. — A motor operated by py- 
romagnetism, or the heating of metals, which, when sub- 
jected to heat, lose while heated their property of being 
magnetizable. 

MOTOR, SERIES. — A motor wound like a series dynamo, 
with fields and armature connected in series with the 
external circuit. 

MUD-DRUM.— A drum placed at the lowest part, gener- 
ally of water tube boilers, to catch sediment, etc. 

MULTIPLE-DRILLING MACHINE.— A drilling machine 
which may carry more than one drilling tool, so that 
holes of various sizes may be drilled in one piece, with- 
out changing drills. 

N 

NEEDLE, MAGNETIC— A bar magnet in the form of a 
needle freely poised so as to permit its magnetic axis to be 
placed in the magnetic meridian. It is usually poised in 
the center, on a jewel pivot. Those which move in a 
horizontal plane are called mariner's, while those which 
move in a vertical plane are called dip needles. 

NEEDLE, MAGNETIC, DECLINATION OF. —The 
declination or movement of the magnetic needle from the 
North pole. Its movement is either east or west. 

NEEDLE, MAGNETIC, DIPPING OF. —A magnetic 
needle which moves only in a vertical plane. It is used 
to ascertain the magnetic inclination, or angle of dip. 

NON-CONDUCTORS.— Materials which offer such high 
resistance to the passage of electricity that it will take 
some other path of less resistance. They are used as 
insulators of electric conductors. Rubber, gutta-percha, 
mica and fibre possess high non-conductive properties. 

NUMBER, DIACRITICAL.— The number of ampere turns 
required to give an iron core half its magnetic saturation. 

O 

ODONTOGRAPH.— A device used in designing the teetb 
of gear wheels. 

OHM. — ^The practical unit of electrical resistance. A re- 
sistance through which an electric current of one ampere, 



579 

or of one coulomb per second, will flow, under a pressure 
of one volt. 

OHM, BOARD OF TRADE (ENGLISH).— The resistance 
of a column of mercury, 106.3 centimetres in length, 
having an area of cross-section of one square millimetre 
at o degrees C. 

OHM, BRITISH ASSOCIATION. — The resistance of a 
cplumn of mercury, 104.9 centimetres in length, having 
an area of cross-section of one square millimetre, a o 
degrees C. 

OHM, LEGAL. — The resistance of a column of mercury 
106 centimetres in length, having a area of cross sec- 
tion of one square milimetre, at o degrees O or 32 degrees 
F. Thie is now the international value of the ohm. 

OLIVER. — A blacksmith's foot-power hammer, used for 
forging bolts and nuts. 

OSMOSE, ELECTRIC— A difference in the level of 
liquids, caused by osmotic action. It takes place when 
two liquids are separated by a porous diaphragm, and a 
strong current is caused to flow through the liquid on one 
side of the diaphragm, into the liquid on the other, the 
latter rising in level. 



PANTELEGRAPHY.-— A system of fac-simile telegraphy 
for transmitting diagrams, charts, etc. 

PARAMAGNETIC. — Possessing magnetic properties, hav- 
ing high permeability for lines of force: opposed to dia- 
magnetic. Iron is most paramagnetic; nickel, cobalt, 
manganese and platinum also have these properties. If 
a bar of paramagnetic substance is suspended near its 
center and placed in a magnetic field, the longer axis will 
place itself parallel with the magnetic field, as a piece of 
wood so suspended in a rapid stream of water would 
place its longer end parallel to the direction of the current. 

PEN, ELECTRIC. — A stylus with a needle oscillated very 
rapidly within, by means of an electric current, with 
which a paper is perforated is such a manner as to be 
used as a stencil for printing a number of copies. 

PERMANENCY, ELECTRIC. —The power of electric 
conductors to retain their conductive properties imchanged 
regardless of the passing of time. 



5«o 

PERMEABILITY, MAGNETIC.-The degree to which 
any substance is permeable to lines of magnetic force; 
its contuctibility of such lines; its property of being the 
agent of magnetic induction. The permeability of a 
material, such as a soft iron core, decrease with the rise 
of the magnetizing force, or, as the saturation increases. 

PHONAUTOGRAPH.— An apparatus, working automatic- 
ally, for the reproduction and registration in visible mark- 
ings of the vibrations of sound waves. 

PHONOZENOGRAPH. — An apparatus for indicating 
whence a distant sound issues. A microphone, telephone 
and Wheatstone bridge, connected together, are necessary 
to operate it. 

PHOTOMETER.— Apparatus for the measurement of light 
given out by any illuminating power or luminous body in 
standard candle power. 

PHOTOPHORE, TROUVE'S.— An instrument containing 
a small incandescent light. Used by physicians in medi- 
cal examinations in cavities of the body. 

PHOTO-TELEGRAPHY.— The reproduction, at a dis- 
tance, of writing, drawings, pictures, etc., by means of 
electricity. The most successful is that of Amstutz. 

PILLOW-BLOCK (sometimes called Pillar of Plumber's- 
block)— A pillow or bed that forms the bearing for a 
shaft, and is made fast to a frame or bed, as the pillow- 
block of an engine. 

PINION. — The smaller of a pair of wheels or train of gears. 

PISTON.— A piece, disc-shaped, that closely fits a cylinder 
bore, as an engine piston, which receives the thrust or 
pressure of the steam, and is caused to reciprocate. 

PITCH-CIRCLES. — The circle in a gear wheel considered 
its diameter for measurements of speed, etc.; it passes 
through the point in the tooth where the face meets the 
flank. 

PLANE, PROOF.— A small conductor for the purpose of 
collecting electricity from bodies charged electrostatically, 
and of which the measurement is then taken. 

PLATE, NEGATIVE. OF ELECTRIC CELL.— The 
negative element or kathode of a battery. In a storage 
battery, the plate connected with the negative terminal 
of the source of charge. In a voltaic cell, the carbon 
element, which is not attacked by the electrolyte. 

PLATE, POSITIVE, OF ELECTRIC CELL.—The posi- 
tive element or anode of a battery. In a storage battery 



SSI 

the plate connected with the positive terminal of the 
source of charge. In a voltaic cell, the zinc element, 
which is attacked by the electrolyte. 

PLOW. — ^The connection from the motor to the current 
conductor, in underground system of distribution for an 
electric railway. It corresponds to the trolley. 

PLUG, SAFETY.— A bar, wire or plate of fusible metal, 
which allows a normal passage of electricity, but which 
fuses, thus breaking the circuit, when an abnormal 
amount tries to pass. 

PLUM-LEVEL. — A tool for determining whether a surface 
or line is horizontal, consisting principally of a plumb- 
bob and straight edge. 

PLUNGER. — A large cylindrical piston-rod used to cause 
a displacement in a cylinder by it size alone. 

POLARITY, MAGNETIC— When iron or other magnet- 
izable substance enters a magnetic field it acquires polar- 
ity, the South pole being the end at which the magnetic 
lines enter and from which they flow, and the North 
pole being the end from which they immerge and toward 
which they flow. 

POLE, NEGATIVE.— The pole or terminal of a battery 
or dynamo by which the current returns to the generator 
after flowing through the external circuit. Careful dis- 
tinction must be made between the positive and negative 
poles and the positive and negative plates of a voltaic 
cell. A terminal connected with a positive plate of an 
electric source (anode) is negative, and the one connected 
with the negative plate (kathode), is positive. The term 
**poles" as properly applied to an electric circuit signifies 
the free ends of a break in such a circuit. When applied 
to the binding posts of a voltaic cell, the fact should be 
fixed in the mind that the end which extends down into 
the electrolyte is the opposite. The negative pole is con- 
nected to the positive plate, and the positive pole to the 
negative plate. In storage batteries this is reversed. 

POTENTIAL, UNIT OF ELECTRIC— The erg. The 
difference of potential existing between two points which 
renders necessary the expenditure of one erg of work to 
force one unit of electricity over the distance between 
those points, is the the unit difference of potential. 

POTEN ITOME TER. — A device somewhat on the principle 
of a Wheatstone bridge for measuring the electromotive 
torce of a battery. A known resistance is placed in opposi- 



582 

tion to the difference of potential to be determined, the 

equality or inequality being shown by the deflection ot 

galvanometer needles. 
POWER, CANDLE.— One candle power is the light given 

out by one standard candle, which is the burning of two 

grains of sperm candle per minute. 
POWER, HORSE, ELECTRIC. — A rate of doing work 

equivalent to 746 watts per second. 
PYROMETER. — A device for measuring temperatures 

above the range of the ordinary thermometer, ordinarily 

operated by the expansion of a metal. In Siemens', a 

platinum wire is exposed to the heat tc be measured, its 

resistance determining the temperature. 

R 

RAILROAD, ELECTRIC, DEPENDENT SYSTEM. — 
The current is conductd from the generating station 
along bare wires above or below the cars and taken off 
and carried to the motors by means of rolling or sliding 
contacts. There are three kinds: the overhead, the un- 
derground and the surface. In the overhead system the 
wires are strung directly above the track; in the under- 
ground system they are placed in a conduit with an open 
slot between the rails in which slides the arm which car- 
ries off the current; in the surface system, the wire is con- 
ducted along the surface of the roadbed and the current 
taken off by a properly arranged contact. 

RAILROAD, ELECTRIC, INDEPENDENT. —A rail- 
road in which the motive power is supplied by primary or 
storage batteries placed in each car, so that each is inde- 
pendent of the others or of any source of energy other 
than its own. 

RE-EVAPORATION. — The evaporation of any water 
there may be in a cylinder after the steam is cut off by 
the heat in the side of the cylinder and piston as the 
pressure falls. 

REFINING OF METALS, ELECTRIC. —The electro- 
lytic refining of metals. 

RELAY. — An instrument at the receiving end of a tele- 
graph line, by means of which a local circuit is opened 
and closed. The impulse which operates the relay may 
be too weak to operate the receiver, but the local circr' 
may be of any strength. 



§83 

KELUCTANCE, MAGNETIC— A term synonymous with 
magnetic resistance. The total number of lines or mag- 

,. n Magnetomotive Force 

netic flux = — 5 ■ . 

Magnetic Reluctance 

RESISTANCE.— The quality of a conductor of electricity 
in virtue of which it resists the passage through it of an 
electric current. To overcome this opposition requires 
electromotive force. The e. m. f. is converted into heat 
energy. Resistances are placed in circuits to cut down 
the e. m. f . or the current. 

RESISTANCE UNIT.— Conductor or part thereof through 
which unit current is obtained by unit e. m. f . Jacobi's is 
the resistance of 25 ft. of copper wire weighing 345 grains. 

REVERSIBILITY OF DYNAMO OR MOTOR.— The 
ability of a dynamo to run as a 'motor when supplied 
with current, or of a motor to run as a dynamo when 
driven by mechanical power. 

R.HEOSTAT. — An adjustable resistance; applied usually 
to a resistance easily varied without opening the circuit, 
the varying values being known. 

ROUTING-MACHINE.— A machine in which a revolving 
cutter cuts away parts of a surface and leaves other parts 
in relief; used by engravers particularly. 



SATURATION, MAGNETIC. —Magnetic substance the 
intensity of magnetization of which has reached its max- 
imum. The development of the largest possible number 
of lines of force in the core of an electromagnet. 

SCREEN, MAGNETIC— An iron box or circuit of wire 
placed over or around a magnet, or other device, to pre- 
vent magnetic induction from taking place, or to screen 
it from external magnetism. 

SCRIBING-BLOCK.— A tool, often called a surface gauge, 
for marking on work the size it is to be when finished. 

SECOHM. — A ternTji sometime used instead of henry, the 
practical unit of self-induction. 

SERIES, THERMO-ELECTRIC— A series of metals ar- 
ranged with reference to their thermo-electric properties, 
so that each is electro-positive to any other following it. 

SHELL. — The external casing, especially of a steam boiler. 



SHELLAC (often spelled Shellack). — A solution applied 
with a brush, for an insulation and a dialectric; com- 
posed largely of resin. 

SHELL-REAMER.— A reamer that fits a mandrel; usually 
coned. 

SHUNT. — A connection in parallel with a portion of an 
electric circuit. An additional path for current. Used 
also as a verb. 

SIDE-CHISEL. — A chisel shaped properly for cutting the 
walls or sides of keyway slots. 

SIDE-TOOL. — A tool for cutting the ends of pieces while 
being held between the centers of a lathe. 

SOLENOID. — An electro-magnetic helix, or cylindrical 
coil of wire, with a soft iron core. Such an electro- 
magnet differs from the ordinary, the core being movable, 
its movements being dependent on the intensity of mag- 
netization. 

SOUNDER. — An instrument, used in telegraphy, consist- 
ing of an electro-magnet acting on a movable lever. It 
is operated by a relay. 

SPECIFIC HEAT OF A SUBSTANCE. — The ratio of 
the amount of heat necessary to raise a given weight of a 
substance one degree in temperature, compared to the 
amount of heat required to raise the same weight of 
water one degree. 

SPIRAL CUTTER. — A milling cutter whose teeth are cut 
spirally instead of parallel to the axis of the bore. 

SPIRIT LEVEL. — Tool for leveling which employs a bubble 
in alcohol, held in a slightly curved glass tube, secured iu 
a frame, to indicate a perfectly horizontal position. 

SPUR WHEEL. — A gear wheel whose pitch surface is a 
cylinder. 

STATICS, ELECTRO. — ^The science of electric charges. 
STEAM-CHEST. — The chest or box into which steam is 

admitted before entering the cylinder. 
STEAM-GAUGE. — Instrument showing the steam pressure. 
STEAM, SATURED.— Steam which is made in contact, 

or is in contact, with water so that there is no heat in it 

except the heat of evaporation. 
STEAM, SUPERHEATED.— Steam heated away from 

the presence of water, thus containing more heat than 

that of evaporation. 
STEAM, WET. — Steam containing free particles of water. 



585 

SUPER-HEATER. ^A sort of secondary boiler, generally 
placed between the main boiler and chimney through 
which the steam passes being thus superheated. 

SUPPLY, UNIT OF ELECTRIC— A unit adopted by 
the English Board of Trade, equal to looo amperes for 
one hour, under pressure of one volt, looo watt-hours, 
or 1.34 horse power for one hour. 

SWITCH. — An apparatus by which circuits are opened and 
closed. 

SYNCHRONISM.— The rhythmatic or silmultaneous oc- 
currence of vibrations, pulsations, etc. It is the principle 
on which the action of certain electrical devices depends. 

SYSTEM, THREE-WIRE.— A system invented by Edison, 
for the distribution of electric current for constant poten- 
tial service, in which three wires are used instead of two, 
one being a neutral wire. Two dynamos are employed. 



TAILINGS. — Errors in the record in automatic telegraphy, 
due to retardation, or to current flowing after the circuit 
is broken. 

TAPE, INSULATING.— A ribbon in the preparation of 
which some insulating material is used. It is for winding 
joints and other exposed places. Rubber tape is used 
largely. 

TREE OR T. — Pipe fitting with two branches at right angles. 

TELEGRAPHY, AUTOMATIC— A system by which a 
perforated sheet, representing dots and dashes, is caused 
to automatically transmit the characters represented. 

TELEGRAPHY, DUPLEX.— The simultaneous transmis- 
mission of two messages over one wire in the same direc- 
tion. Gray's harmonic multiple system is for sending 
musical notes of various pitch over one wire. For each 
tone a separate message is transmitted. 

TELEPHONE. — A device or combination of devices, for 
the electric transmission of sounds, especially articulate 
speech. 

TEMPER.— The degree of hardness of steel. It is first 
heated, then plunged into a cooling bath. Each variety 
of steel and work requires a different temper. 

THERAPEUTICS, ELECTRO, or ELECTRO-THER- 
APY. — The use of electricity in the curing of diseases. 



586 

THERMOSTAT. — An instrument operated by the expan- 
sion of a body by heat, which opens or closes a circuit, 
thus automatically maintaining a certain temperature. 

THERMAL-UNIT. — Amount of heat necessary to raise a 
pound of water from 39.1 to 40. I degrees F. 

THROW-LINE. — The line described by a part actuated 
by an eccentric. 

TORQUE. — Turning movement of the force exerted on a 
dynamo armature to rotate it. Torsion around an axis. 

TRACTION, MAGNETIC— The force which tends to 
keep a magnet in contact with its armature. Must not 
be confused with magnetic attraction. 

TRANSFORMER.— An induction coil used in systems of 
lighting by alternating current to transform or convert 
high initial electromotive force to low initial electromotive 
force such as can be conveniently and safely used for 
commercial work, or the reverse. The transformer is 
employed because high voltage currents are transmitted 
more economically than those of low voltage. 

TRANSMITTER, CARBON.— The carbon button trans- 
mitter in a telephone. 

TRIP-HAMMER. — Hammer w^hose helve btam is tripped 
by a cam. It is used mostly in forging. 

TROLLEY. — A grooved wheel moving on the overhead 
conductor of electric railway lines, and receiving from it 
the current to operate the motor and move the car. 

TRUNDLE. — A gear-wheel whose engaging surfaces are 
rungs instead of teeth, as in a lantern. 

TUBES, GEISSLER, GLASS VACUUM. —Tubes of a 
great variety of forms used to illustrate the luminous 
effects of electric discharges through gases. 

TURN, AMPERE. — The passage of one ampere around 
a circle, once. A single turn of wire in a coil through 
which but one ampere passes, sometimes called ampere- 
winding. The ampere- turns in a coil determine the 
magneto-motive force of the magnet. 

TUYERE. — Nozzle through which air is forced into a cupo- 
la, or an ordinary blacksmith's fire, operated with bellows. 

TWIN-MILLS. — Milling cutters with teeth on their side 
faces and circumferences. They are operated in pairs. 



I 587 

u 

UNIT, ABSOLUTE. —A unit based upon the centimetre, 
gramme and second. 

UNITS, PRACTICAL.— The volt, ohm, ampere, coulomb, 
watt and other units. These are multiples of C. G. S. 
units absolute, which are too small for convenient use. 

U. S. STANDARD.— A V-shaped thread with a flat sur- 
face at the top and bottom. 

V 

VACUUM, ABSOLUTE.— A space containing no material 
substance. The existence of such a space is doubtful. 

VALVE-STEM. — The rod connecting the valve with me- 
chanism outside the steam chest. 

VIBRATION, PERIOD OF.— The time required for an 
oscillating body to make a vibration. 

VIBRATION, SYMPATHETIC. — Vibration caused in a 
body by the placing of a vibrating body in its immediate 
vicinity: as a tuning fork made to sound by placing a 
vibrating fork near it. 

VOLT. — The practical unit of electrical pressure, or elec- 
tromotive force. The pressure required to move one 
ampere against a resistance of one ohm. The electro- 
motive force induced in a conductor, usually an armature 
coil, which is cutting one hundred million magnetic lines 
(of force) per second. 

VOLTMETER. — An instrument for direct reading on a 
scale the volts or electromotive force in a circuit, or the 
difference of potential between any two points thereof. 
They are connected on a shunt to the circle, or in parallel. 

W 

WALKING-BEAM. — The oscillating beam in the engine 
of that name to which are attached the connecting rod to 
the piston on one end, and the connecting rod to the 
crank on the other. 

WATT. — The unit of electric activity or power equal to 
one joule per second or 10,000,000 ergs per second. 

WELDING, ELECTRIC— Welding metals by the appli- 
cation of electricity. This is done by passing a heavy 
current through the point of junction at a low e. m. f., or 
by forming a voltaic arc between the parts to be welded. 



5«« 

WINDING SERIES.— A dynamo or motor field ha\dng 
but one coil which is connected in series with the arma- 
ture and the outside circuit. 

WORK, ELECTRIC— The joule. One volt-coulomb or 
one watt for one second. 

WORK, UNIT OF.— A unit force acting through a unit 
distance gives one uni«t of work. In the C. G. S. system 
the unit of work is the erg equal to a force of one dyne 
acting through a distance of one centimetre. The prac- 
tical unit is the joule = 10,000,000 ergs. The British 
unit is the foot-pound and is equal to a force of one 
foot. The ratio between the two systems is: I foot-pound 
«= 13,563,000 ergs (about) = 1.3563 joules (about). 

Y-Z 

YOKE. — A piece that carries or secures two or more other 
pieces, and adjusts their distance apart. That part of a 
dynamo frame which connects the limbs of the field 
magnets. 

ZINC, AMALGAMATION OF.— The coating of amal- 
gamation of zinc plates. The amalgam is a combina- 
tion or alloy. The most important constituent is mercury. 



INDIA-RUBBER, TESTS FOR. 

India-rubber should not give any sign of superficial 
cracks on being bent to an angle of 180® after five hours' 
exposure in a closed air bath to a temperature of 125 ^ Cent. 

Rubber containing not more than 50 per cent, by weight 
of metallic oxides should strech to five times its length 
without breaking. Pure caoutchouc free from all foreign 
matter, except the sulphur necessary for its vulcanization, 
should stretch seven times its length without breaking. 
The extension measured immediately after rupture should 
not exceed over 12 per cent, of the original length of the 
test-piece. The test-pieces should be from 3 to 12 milli- 
metres wide, and not more than 6 millimetres thick and 3 
centimetres long. The percentage of ash gives a certam 
indication of the degree of softness, and may form a basis 
for the choice between different qualities for certain pur- 
poses. Any excess of sulphur over that required for vul- 
canisation should be removed at the works, and should not 
appear on the surface of any object. 



